Without anyone knowing your name or address?
Localbitcoins or a bitcoin atm (if available in your place). The former option needs you to meet someone physically and trade face-to-face. You don't need to give him/her anything about you, just setup a place where you two would meet. The latter is as easy as scanning a qr code and wait for the cash to come out of the machine.
Don't ATM's require you to have a bunch of ID and things like that? They know who you are?
IDK I never used a BitCoin ATM.