I think you're a good candidate, but I would like to say that your grammar is not correct. Sorry, but I am a Grammar Nazi.
Hello:
I'm Michelle, and I'm 15 years old.
I know I only just started, but I would like to be a moderator, because I'm a very helpful person.
I have experience with moderator rank.
i've been mod on 4 (four is more proper; numbers under 10 and above or equal to zero should be written out) different servers.
I have correct grammar.
Thanks for your attention 