Train from Frankfurt to Trier

I had the exact same questions you had last year. I did the GAS tour last year and by myself! It takes 3 hours to get to Trier from the Frankfurt airport and this was the first time I had no jet lag by the time I got to the hotel! You get off the plane and get your luggage ( customs first then luggage) and then make your way to the ticket booth. I was very fortunate, I met a German couple on the plane that got me to the ticket booth which is a bit of a distance from the luggage area. The man at the ticket booth spoke perfect English and was very nice and patient. He explained where to go to catch the first train and the times of the first and second trains. Do not get on any train that pulls in, the trains are on time so if a train comes in and it is not the right time, it is not your train.

I had to take an escalator downstairs from the ticket booth and found the first train station in the airport easily. Took that train, got off at the stop I was told to get off. The second train was not at that spot, had to find the second train, asked a worker, found a long hallway and looked for the correct sign for my train, it was the last sign at the very end of the hallway. In the wall was an elevator, took it up and there was the platform. Took the train at the correct time. That second train takes you along the Mosel river I believe and it is beautiful. Scenery during the train ride is wonderful. Got off and took a cab to the hotel. My cab driver did not need the directions I brought,just in case to get to the hotel.

It was fine, I did it without a hitch, by myself and asked people for help along the way!

You have more than one person with you so that is even better, one person watches the luggage the other can ask if you need help. Do not stress over it, it is fine.

The GAS tour was wonderful, I would love to do it again.

Have a great time, safe travels, you will not get lost, you will be fine. People speak English and I also pointed to my directions if they did not.

Never had any language issues at Deutsche Bahn. The train station is right at the airport and easy to find by following the Train icon directional signs. The ticket desk is at the "Fernbahnhof" (long distance train station), but you will depart from the adjoining "Regionalbahnhof" (regional train station). The least expensive way is to ask to go by regional train, for which there is a special ticket called a "Quer durchs Land" ticket (Day ticket for Germany) if it is a weekday costing 52 EUR for 2, or "Schoenes Wochenende" ticket (Weekend ticket) if it is a weekend costing 44 EUR. Ask for a routing with only one connection, preferably Koblenz.

At Koblenz, your connecting time is usually about 12 minutes, which sounds quick, but is actually plenty of time. You will check the train board to see your next track, have to walk down a stairway or ramp to a tunnel underneath the tracks, walk a short way to your next track and then upstairs to the platform. They also have elevators. Usually it is from track 1 to track 9, but these can change, so check first. The Deutsche Bahn agent will also give you a piece of paper with the train times and track numbers of the journey you want.

If you miss a connection, your ticket will be good on any regional train so you can just wait for the next one. From Koblenz, they go twice an hour at 6 and 25 past the hour (generally).

Finally, anyone who appears to be younger than 40 will probably know some English. Just start with "Bitte, sprechen Sie Englisch", and go from there. People are generally very helpful.

Edit- Those ticket prices will be 2 EUR more than what I said because you will be using the ticket window. Sounds like it might be a bit early for you to learn how to use ticket vending machines, which is how most Germans buy regional train tickets.

While I have some understanding of the German language and can speak in simple terms, I've never had a problem navigating trains, etc. in Germany. My procedures are to check the German train website for the schedule of trains from the Frankfurt Airport (are you departing from the airport or city?) to my destination and write down on a small Post-it note the possible trains I could catch upon arrival. Note connections for your peace of mind. Once it's clear which train to make, I highlight it on the note and hand it to the rail clerk at the ticket booth. The tickets are purchased and often the clerk will give you the general direction to your train. Making connections at train stations is easy...just see the signs....don't overthink the matter.. Upon arriving at my destination city and if taking a taxi, I hand the driver a Post-it note with the name, address and phone number of the hotel. Never a problem. Have a great trip.

"We do not speak any German."

No sweat.

Airport signage to the Regionalbahnhof is in English.
http://anneschuessler.com/wp-content/uploads/2012/04/P10201091.jpg

The ticket personnel at the counter and the ticket machines do English too. At FRA you use the same machines for both DB tickets and local RMV tickets. See logos on machines:
https://www.rmv.de/linkableblob/Zentral/52958-39356/original/Fahrkartenautomat_neu.jpg
http://3.bp.blogspot.com/-KVibXidVM-E/Ujc4HYBzUAI/AAAAAAAAHWk/wxQQR0dr6R4/s1600/IMG_1814.jpg

Underground platforms at the Regionalbahnhof show destinations, departure times and track numbers.
http://www.bahnbilder.de/bilder/die-s8-wartet-unterirdischen-regionalbahnhof-147975.jpg

Some clarifications are needed...

TRAIN ROUTE:

The regional trains to Trier are fastest (3 hours) with a 2-train connection that uses regional express trains. More connections = more time and more potential hassles. But there are TWO different routes you can take - one via KOBLENZ (along the Rhine and Mosel Rivers) and another via SAARBRÜCKEN (not so much scenery.) So if you want that scenic route you should look for a schedule at the DB Itinerary Page by entering Koblenz Hbf as a stopover station. (Do not enter any stopover time.) If you do not do this, the resulting schedules will include both routes.

Also, you should check the "only local transport" box; this will yield only schedules for regional trains (for better schedules and pricing.)

When the schedules pop up, look under the "Chg." column for a schedule with "1" change and avoid the schedules with multiple changes if possible.

TICKETS:

Using day passes like the QdL ticket for €52 as previously suggested is possible, but you cannot leave FRA before 9:00 a.m. on such a ticket. What day of the week and what time do you think you'll be leaving FRA?

Buy your tickets at the Regionalbahnhof station once you get there rather than online.

Also, neither the QdL or the Happy Weekend ticket is your cheapest option. Use this 2-ticket combo instead - it's good for either route and will cost €38.60 total:

RMV ticket for two to Mainz (€9.60) (you pass through Mainz anyway, no matter your route.)
Rheinland-Pfalz ticket (day pass for two) for the remainder of your trip (€29.)

The above ticket strategy works for weekdays or on weekends. However, while the RMV ticket can be used at any hour on weekdays, the R-P ticket will be valid only after 9 am. So whatever your route, and whether you have a change of train in Mainz or not, you may only use a train that departs Mainz station after 9:00. On Saturday or Sunday, this is not a problem.

A couple things:
The 24 hour clock is used for train times (so 1400 is 2pm)
Dates are written day/month/year, so 10/9/17 is Sept 10, NOT Oct 9.

When checking train times on the DB website, you can choose Show Details and Show Intermediate Stops. It's good to know the stop before yours, so you can gather up your things and be ready to get off.
Also, most schedules show the track number, so you'll know where to go for your connecting train. I do, however, always double check.

Have a great time! The scenery along the Rhein and Mosel is wonderful.

You've gotten terrific advice.

I'll just add that you should print out a google map of the driving route from the Trier Train station to the hotel that is used on this tour. It is slightly odd as it's also an Assisted Living Facility and it is not well-known by the taxi drivers. They are all extremely helpful, just puzzled. Mine was upset because the facility stops taxis at a barrier to the parking lot instead of letting them drive in. It is just about 50 feet to the front door but my driver was miffed that he couldn't take me any further. I thought that was very sweet! The rooms are actually studio apartments, breakfast is great and staff is very nice.

And yes, I would take a taxi, not walk. It's not a hard walk, just a lot of pedestrian streets and much easier to pay for a taxi.

I know you will enjoy this tour! Such fun!

RMV ticket for two to Mainz (€9.60) (you pass through Mainz anyway, no
matter your route.)

Right. Even if you are fortunate enough to catch one of the REs that go directly to Koblenz, they will stop in Mainz, and the RMV ticket will cover you to Mainz and the Rheinland-Pfalz-Ticket (as long is is on a weekend day or after 9 AM on a workday) will cover you to Koblenz.

Thank you all for taking the time to respond to my question. I now have lots of good info and feel better prepared. I have traveled to Europe several times but have always had at least a working knowledge of the language of the countries I have visited. German is completely new to me in spite of my attempts to familiarize myself with the language via Babbel and Duolingo apps!