JOINING BOOST & ACTIVATING YOUR SIM
SETUP & PHONE SUPPORT
RECHARGE & NETWORK SUPPORT
You're going to have to contact Google directly for this
If you are referring to your Gmail Account go to gmail.com and press the Forgot Password link enter your email address and follow the instructions on how to reset your password.
Boost would have no record of that information.The above advice from @JamesG would apply to this situation.Good LuckSP