train travel from Frankfort to Freiburg and from Freiburg to Paris

The website of the German railways is the one you need: www.bahn.com/en/view/index.shtml
Advance booking gives an enormous discount: the normal ticket price for Freiburg-Paris is EUR 117, advance booking is EUR 39. The fast train for Frankfurt to Freiburg will probably also be considerable cheaper when bought well in time.
Booking is simple: credit card and an emailed pdf. Have the credit card with which you've bought the tickets with you on the train. They might want to see it for identification.

Best is almost always the site of the railway company running the trains. In this case DB (German Railways): https://www.bahn.com/en/view/index.shtml
SNCF (French Railways) would also work for the leg to Paris, but you might as well buy both from DB.
One point, please try and spell place names correctly or you will not be able to find them on the site or book tickets

• I assume you mean Frankfurt, but there are two Frankfurt's in Germany: Frankfurt (Main) and Frankfurt (Oder). And in the first case are you starting from the city centre ("Frankfurt (Main) Hbf"), or the airport (*Frankfurt (Main) Flughafen").
• There is more than one "Freiburg" in Germany. The one you almost certainly mean is Freiburg (Breisgau).

There are hourly trains from Frankfurt (Main) to Freiburg (Breisgau).
There is one very early train per day from Freiburg (Breisgau) to Paris that does not require a change, plus lots more options involving changes:

Freiburg(Breisgau) Hbf 06:54
Paris Gare de Lyon 10:37

There is a Frankfort, but it is in Kentucky. No train service between them.

I like to use this Bahn website for train schedules in Europe.

Why are you going from Frankfurt to Paris via Freiburg? It would be faster to go via Strasbourg (or Saarbrücken). If you have a reason to stop in Freiburg, for how long?

Thank you everyone for your help and for such detail. I don't know why I always want to spell Frankfurt, Frankfort. I flying into Frankfurt and then traveling to visit my brother in Freiburg for a few days. Then I have a conference in Paris. That is why it is a round about route. Then off to Venice to visit my daughter.

Yes, it is all very easily done with many frequent trains. The biggest decision on your part is how you want to get from the airport to Freiburg. There are direct trains every 2 hours at 51 past the odd hours (9:51, 11:51, etc) or trains with a single connection in Mannheim at the even hours. The walk up price is 69 EUR and I would recommend that as you can never be sure your flight will land on time and if there will be any immigration delays or luggage delays.
Or you could land and take one of the frequent local trains into Frankfurt, store your luggage in a locker and tour the town for a few hours. Then, you can take a direct train to Freiburg for 29 EUR bought 90 days in advance, or a train with a single connection in Karlsruhe for 19 EUR.
By all means, buy your ticket from Freiburg to Paris 90 days ahead to get a good price.