Pretty much anywhere in France within a comfortable range from your home airfield (or beyond, you could always overnight somewhere on this side of the channel).
One suggestion would be to get hold of the France trip kit from Jeppesen and corresponding VFR charts (or even the DGAC's VFR guide, which comes with two one-mils covering all of France metropolitaine). What I do is read the aerodrome information on the Bottlang, and whichever looks nice, that's where I fly, simple as that
France is quite possibly the most GA friendly country in Europe, and if you can do your radio in French (giving you access to the really small places) then you could just cut off your engine(s) pretty much anywhere in the country and glide yourself into an airfield, there is that many of them
