Hello! It doesn't have to be just one character, but it has to be obvious who the 'hero' is! You can include side/support (or enemy) characters in your concept sheet/illustration.
As far as UV's go, it's not required for submission! If you're able to showcase the model with textures and everything to present it as you'd like, you're set! Hope this cleared up some confusion.
@marc i did'nt understand the procedure to create a new topic
and where do i create it