Just be a good normal member. Post in the forum, engage in discussions, start some good topics, help people out, chat to people.
Most people get bored of that after a couple of weeks. If you stick around for a long time and still enjoy the community here, and we think it'd be useful to have you on the team, that's when *we* look at it.
It's well-known that we do NOT accept applications for moderators - they're all chosen by the admins from the people we know will be good staff. Asking to become a moderator actually shows us that the member doesn't know the way this forum works, so we don't pick anyone who asks.
Don't *TRY* to become staff, because it won't work. Just be a normal member, and you might end up in a position where staff is a good option, but you might not.