TLV?? You must mean TGV (train à grande vitesse) - the French high-speed train?!

I'm not very familiar with driving in France so can't give any advice on that.
Taking a train to the Loire valley is very easy though.
There are actually about three trains a day from CDG airport (yes there is a real railway station at the airport) to the Loire Valley, so just try to get a ticket for one of those trains. The train station is below the terminal 2 terminals, just follow the signs or if you arrive at terminal 1 then take a bus to terminal 2. Takes about 2-3 hours from CDG to the region.

Otherwise all the trains to the Loire Valley leave from Gare Montparnasse in southern Paris, there are trains every hour to various destinations in the region, during rushhour every 30 mins. From CDG there is a direct bus to Gare Montparnasse which is very convenient. I think it leaves every 30 mins but I'm sure you can find the timetable on the internet.
Tickets for the trains can be booked on the internet www.sncf.fr

If you want to visit castles in the region you need to rent a car or use buy tickets for bus excursions, the locations of the castles were not really selected to make transportation as easy as possible for tourist a few hundred years later.

I actually studied French in the Loire Valley in a lovely little city called Angers (about 150000 inhabitants). Very nice and clean city with a nice castle to visit. You can reach the city by TGV.
Making excursions from that city was pretty easy, 1-2 hours to most places of interest including all the castles in the region, the Atlantic coast and Brittany.

Suggestions for places to visit...
-Well a few castles of course like Chennonceau and Chambord (not sure if the spelling is correct).
-Brittany which is right north of the Loire Valley. Visit the lovely little city of St Malo just by the English Channel. There is also a very famous place called Mont St Michel which is a city built on a high rock, you probably need to see a photo of it to understand what I mean.
-The Atlantic Coast, there are a few nice small cities not too far from the larger city Nantes like Vannes.
-When I was there I also visited a combined theatre play and light show in a small village called Puy-du-fou which was absolutely fantastic. Supposed to be famous all over France and definitely worth a visit if you can get tickets.
It's a huge area they play on with a real castle in the background which actually burns down right in front of you during the play.
Never seen anything like it.