how to play halo 3 online?

[Ben]

well, hello i just got a xbox 360 and 2 month substription and i have signed up and everything well i went into the game where it says campaign matchmaking e.c.t but well it tells me how many people are playing but how do i join them it please help me =[] thanks ben

 

[drama]

dude go into matchmaking rite
and ur goin to be da only player in da lobby and on the side its going to say start matchmaking
choose that and then wait players will join in cause their looking to play matchamking too.

add me my gt:
s3rius jon3s