I assume you’re wanting to stay in/near Fort William? Otherwise camping somewhere like the beach at Arisaig is very cool (or miserable of course coz Scotland). The next morning you just drive to the park and ride at the High School
We have stayed at great glen water park the last 5 or 6 years it’s a bit of a drive, 30 minutes or so but the views are good so I don’t mind the drive we get a cabin that sleeps 6/8 for about £350 for fri/sat/sun nights so about £20 a night each 3 bedrooms and a kitchen and decent size lounge to hang out in after the compulsory trip to Morrison’s in fort Bill. pub/restaurant and swimming pool on site and great views of the loch it’s nice and chilled compared to the places near fort Bill.