would you suggest sticking to legs no longer than 200nm?
Only you can answer that.
Have you got a PPL?
You need to establish your aircraft's actual range, for various power settings, and then plan the route according to that, and what airports are available which can accept your flight, have avgas, etc.
200nm sounds OK for a C152. Its zero-fuel range in best-economy cruise power is more than that (300nm? - it is 10 years since I flew them) but in reality you will be limited by airports.