Basic class limit is 10 with live fire done in two relays.
I dislike having more than 4-5 shooters on the line hot unless I have an assistant.
I'll bump that number up slightly towards the end of a class if I have permit holder attendees joining in who are just shooting a requal.
The classes in Pahrump seldom max out.
As far as prep for a basic class it's sort of a catch 22.
If you don't have any training there's a possibility that pre-class practice may just be ingraining bad habits that you'll just need to clean up later.
A "clean slate" as it were may actually be more productive.
If you are going to be shooting before you come to class, the one universl thing everyone needs to perfect and maintain is trigger finger "discipline, i.e on target, on trigger; off target, off trigger.