Is there a fee to camp up there? If so, how much and where do I go to pay and reserve a spot?

Be aware that road to Cascade is closed if you come in from the Midway side. To road in from Provo puts you at the upper parking lot. Long way downhill to the springs. If you have some walking challenges it's a long way back uphill.

No camping at Cascade Springs, but there are sites, improved and non improved along the road leading up to there. Go to recreation.gov for starters.