If you haven't roleplayed with anyone yet, anything is fair game, really.
Even after you've begun roleplaying, you are free to change your character if you wish. Just be aware the more tied to other characters you become, the more inconsiderate it can become to make unexpected changes without consulting with the other people first.
Again though, you are free to do as you wish with your own character, just be wary of repercussions if you do it, and try to be thoughtful.
It sounds like you aren't engaged with anyone currently, so you should be completely fine, though.
Even after you've begun roleplaying, you are free to change your character if you wish. Just be aware the more tied to other characters you become, the more inconsiderate it can become to make unexpected changes without consulting with the other people first.
Again though, you are free to do as you wish with your own character, just be wary of repercussions if you do it, and try to be thoughtful.
It sounds like you aren't engaged with anyone currently, so you should be completely fine, though.