Road Tripping Around Westen Europe!

Hey there!

Me and two mates of mine are planning to road trip around Westen Europe including France, Belguim, Germany, Czech, Austria, Italy and Switzerland in that order.
We have booked a campervan for 2 weeks, from the 31st of May to the 13th of June. We also decided we are going to film it all and make a little documentary about it all, heres a little 'trailer' we made the other day.

Protected content

I wanted to ask a few questions to anyone who might have done something like this before.

What are the best things to see, considering we are driving and camping in these countries?
Is it easy to camp just anywhere or should we book campsites?
Are there border restrictions in some of the countries?

Would be great if anyone could help me out,
Cheers,
Tristan E