Everyone has different expectations regarding a holiday. Some people want to relax at a pool, some want to explre historic sites, others want to be active outdoors. But a holiday that includes travelling with a tent and sleeping outdoors is even more challenging.
Europe is diverse. You can swim in the Mediterranian Sea, explore the ancient worlds of Greece and Italy, climb mountains, experience midummer nights far in the North, see volcanos, geysers and glacial ice and walk for days and weeks in woods and forests.
I try to find campsites in places that are not crowded, close to or right in the middle of nature and sometimes even in a National Park. Ideally a campsite is just for tents, maybe with a few caravans and doesn't have too many cars.