i remember my password and i think i know my username but is there any way to reset your password when you log in to the game menu?
You'd have to do that through the forum itself. If you click your username in the top left corner (when logged in), click account settings from the drop-down menu and you can change your password from the prompts in there. You will need your old password in order to do this, however.
Though I'm not sure if usernames are recoverable... Should it be the same as your guest name, you'll likely be fine anyways