I would call them and ask, maybe save yourself a trip.
I believe you can now shoot steel case since they redid the range. I assume you mean how young can one shoot. I believe as long as your with an adult its pretty young. However you can only shoot smaller rifle calibers unless your a member. I have shot 9mm rifle and 22 rifle with no issue. If you have an AR type rifle you need to be a member. I would call to confirm all of this. They are happy to help.
Thanks! Your answer is awaiting moderation.