I strongly encourage you to do race-oriented group rides before you race. It's not the same as racing but it's a lot closer than riding by yourself. You'll learn something about the pace and safely riding in groups.

But you don't need to join a club to do so- most have open rides. So you can try out all the local clubs and see who you like before you join. You can race without joining a club, but you will pay a small unattached rider fee, and you should have a plain jersey or at least one that's not got logos of well known race team sponsors on it.