If you approach other people and ask them to jump with you, then I think its fair for them to ask slots. Whereas if someone more experienced asks you if you want to jump with them, then that assumes they're gonna go anyway. If you try and make friends with lots of people you might get more jumps with people.
Im lucky that theres quite a few people with cat 8 at my uni club, and theres a few of us with FS1 (cat 10, whatever) so we have friends we can jump with.
But as the most jumps in the club is only about 150, none of us are coaches, so its just fun 4 1-way formations You should always pay for good coaches. When you get your cat 10 (or whatever it is in the states) then just start jumping with friends. Ive been told its like driving. You dont learn until you pass your test.