I've completely forgotten my school password and my locker code
How did you forget both codes?
I'm not sure. I just did.
It's ok if you forgot the password. There must be some way out so you should talk to the concerned person, they'll help you.
I now want to pretend that I'm a mad hacker who's been locked out of his account.
It's good to make light of the situation and make fun of it in a way. it shows a good sense of humor.