I'd go for 12 Constitution and 12 Charisma if I were you, not because I think it reflects role playing as Bilbo better, but for general enjoyment - the game may seem pretty hard for a new player!
This is probably the right answer. Either reduce Charisma or Wisdom to 12 and boost constitution to 12 so you are not getting killed all the time. A high dexterity (controlling AC) and a moderate constitution (controlling HP) could help you stay alive in combat.
