Train from Boppard to Frankfurt airport 9/8

I think novices should stick with direct trains rather than counting on making a change of train. Most departures from Boppard involve a change, but there's a direct RE (regional express) train to Frankfurt (M) Flughafen that, if on time, will get you there extra-early:

11:16 - 12:34

There's another (13:16 - 14:34) but I can't say whether that gets you to the terminal early enough. That's between you, your airline, and God. I'd go with the first option.

Fare is €24.10 each. Buy one DB ticket for two at the station or online on the day of travel - or earlier if you wish.

https://reiseauskunft.bahn.de/bin/query.exe/en

In the past, I've always allowed myself 2 - 2½ hrs at FRA, but I know Frankfurt airport, and with the difficulties today, and since you are not familiar with the airport, I would suggest more than 3 hours. There is a direct RE from Boppard to the Frankfurt airport arriving at 12:34, about 3¾ hour ahead of your flight time. It leaves Boppard at 11:16, and has no change of trains. I think the next train is an hour later.

Use the German Rail schedule and fare website to look for train connections. Use Boppard Hbf and Frankfurt (Main) Flughafen. There are two train stations at FRA. The farther out Fernbahnhof is for high speed trains like ICE, IC, etc. The closer in RegenionalBhf is for regional trains like the RE.

Great responses, thank you very much.

"I think the next train is an hour later."

Right, the 12:44 departure from Boppard is the next one after 11:44 - but it's not direct - it requires a change of train and platform in Mainz - and because it uses the "milk-run" trains, it will require two full hours, with arrival at FRA at 14:43 (if on time.) This option will leave you with a time cushion at the airport of only 1.7 hours.