Interrailing in Europe, help with startplaces!

Hi!

Im going for a traintrip for like a month or more if the money is spent well, starting from the beginning of May.
I will buy interrail card in Europe and I was thinking of going from Norma (south of rome) in Italy to northern italy and go ahead somewhere from there.

I want to begin with a nice place like Dune de pyla to exercise Wingovers really hard and try to learn Helicolanding. Afterwards I wanna go to a place like Annecy and practice Spirals and Colapses where I have enough altitude.

When im ready I wish to try an acrocourse

I dont have a Car and no companion so what Im after is places where it's not hard to get to takeoff and not to hard to meet other pilots. Please, any ideas? Everywhere in Europe is fine.

Regards
Carl