Local Site
When I first started out, I had my newly bought equipment, no air, a bit of paint and no real experience of managing my marker and its air system, so I phoned up my local site and asked if I could attend on a day when he was just doing as bit of maintenance so that I could be taught safety with regards to air fills, and just get a feel for firing my marker on his feild.
I was given an induction on site health and safety and air fills, and I felt more confident when I attended my first walk-on. Also, I put about 300 rounds through my marker just to get a feel of using it.
Why not try something similair with your local site?