Im in training trying to pick characters for both teams, when i hit enter then try to pick another character for the red team, it changes the character i picked for the blue team. How do i change the character in the red team? Is there a keybind for it??

p1 and p2 start in m.u.g.e.n has different keybinds, so yes, there's another keybind for it

The numpad keys are the controls for the player 2 , also you can change the keybind on the configuration