Catching TGV train from Gare De Lyon

You can visually "walk" through most major French Gares (train stations) at this website: Gares360. The app may only be available at the French App Store? We've found it very helpful.

All the stations are well marked with signs. Just like finding you way through an airport. Find the departure board, it will show the platform number - generally about 15 to 30 mins prior to departure so don't panic if you don't see you train listed. Know the train number and final stop. Go to the platform and wait for your train. And if concerned don't be shy about asking anyone else standing around if the train is going to X.

You can familiarize your self with the station by going to http://parisbytrain.com/gare-de-lyon-photos/. Gare de Lyon is a large train station but there are plenty of signs. The first time I used the station, I arrived 30 minutes before departure time and we had plenty of time to find the train and the track.

Just saw this site http://parisbytrain.com/gare-de-lyon-photos/ and found that the RER train will come at Level-2 and then you need to take escalators to come to Level-0 to take TGV train. I guess that my understanding is correct

Are all the signs and display board in English language and easy to understand?

Gare de Lyon has a trick, which only the French could think of. It is divided into two "Halls". See plan here: http://www.garedelyon.fr/wp-content/uploads/2013/10/plan-services-gare-de-lyon-1.png

Hall 1, the older part, has platforms A to N (yes letters).
Hall 2, the newer part, has platforms 5 to 23 (numbered, odd numbers only).
Hall 3 is the underground area.

When you arrive (by taxi at ground level, or by métro or RER via Hall 3) look at the video screens to find your train. It will be listed (about 90+ minutes in advance) and will say "Hall 1" or Hall 2". Follow signs to the correct area and wait.
About 15-20 minutes before departure, the video will change to show the actual platform number, but as you are already in the correct "hall", it is only a short walk.

Once you know the hall 1/hall 2 trick it is easy.
There are a few places you can buy food and drink in both halls, but only limited seating. If you find a seat hang on to it, if you go away someone else will have taken your place when you return.

Some signs have French followed by English, German and Italian (can't remember the order). The video screens are obvious.
When you arrive by métro/RER, you are at level -3. Just follow signs "Grandes Lignes" (main lines) and keep going up until you see a video screen with your train on it and signs to Hall 1 or Hall 2.