Tutorial Replay

hi there.

i started playing marathon, but during the tutorial i noticed my username was my full legal name. that wasnt fun, so i exited marathon, and fixed it in bungie account settings. then, when i returned, it simply put me in the startup screen. is there any way i can replay the tutorial, because i don't know how to play this game. also there is some sort of cosmetic awarded for completing the tutorial, is there any way for me to get it?