pre book or what

I`m off to Europe next weekend (sun 22) and have a route and some accomadtion booked , what I was wondering is I need a campsite south of stuttgart, do I need to book one or can I find one when ever I feel the need to stop for the night, are they easily and ready available around the Black Forest ?

>>do I need to book one or can I find one whenever I feel the need to stop

I don't think anyone could answer with any certainty.

Stuttgart is quite a bit to the east of the Black Forest.

Tim