1. You don't just become admin. Even if you were to get a position, you'd start at moderator and work your way up.
2. You don't ask to be a staff member either. You just show you're quality material.
How do you do that?
Be nice to staff and players.
Help out without being asked.
Don't break any rules.
Be a good person.
Staff notice people who help all the time, and then we vote if we think you're worthy of a position. You can say you're interested, but don't ask to be a staff member more than just now or you'll look pushy, and we don't want pushy people.
Also, it helps if you show you want the position to help people, not just to have power.