It's different for each club. Some clubs just base it off stats (terrible idea) and others base it off of a combination of maturity and how long a player has been in the club.
Imagine a club is like a company, you must make the boss happy by being loyal, contribute to the club, then u can me admin.
The best way is to be kind, loyal and helpful to the members. Stay longer in the club and try not to make too many visits as the owner may dislike it. Also try to upgrade as your chances might be higher. ~
Kelsey as a word of advice, none of the sexual references that you said in my club chat were advantageous to becoming an admin. You left without saying anything but might find more success in another club anyways