What if i dont know wha my email or password is for my gamer tag?

And if i do recover it will i have all my game info back like will i still be the same pertige on call of dutyWhat if i dont know wha my email or password is for my gamer tag?im not sure about being the same prestige as i think that is saved to your hard drive. when you recover your gamertag i think you just get your achievments back.What if i dont know wha my email or password is for my gamer tag?you will keep all ur prestiges and achievmements