Can 15 year old have a membership to shoot alone with parent permission if not is there a minor membership to were he can be by himself if so what guns can he shoot and how much

Nope, you or another adult will have ti be with a minor.

Nope , no minors can posses a firearm and use without and adult supervision.

No this is actually a law issue, he'll need to have a guardian or parent with him supervising otherwise that is minor in possession of a firearm and providing access of a firearm to minor. This will be anywhere in the US.

No