People of all shapes can cosplay. I just saw a hexagon in a Hatsune Miku cosplay last week.
Anyway, glad to hear you've decided to start cosplaying. The people here are wicked helpful and love to give advice from experience, so don't feel shy about asking questions.
facebook page // nh cosplay events
COSPLAYS IN PROGRESS
Constructing : Soren (Fire Emblem), Fox (RWBY)
Upgrading : Sheik (armor), Cloud (wig and armor)