Hi
You could just try Burrs Country Park at Bury. I think it's a caravan club site so not the cheapest but lots of people rate it. Other than than that why not try a pub stopover there's quite a few on here.

I second the pub stops, then you can just go, if it starts raining, you can turn around and go the other way!
We quite often get to the main road from our house and just say, left, right, or straight on and that's as far as the plans go!

My advice.
Join The Caravan Club. look on line for a site near to you and book it for a week end. You will then soon get used to all the bits a bobs of your van as well as seeing what other people do. We wild Camp a bit but for our main holiday we always use their vast array of sites. We park up and tow a small car which we use for site seeing, shopping ect.
Have a great time.