They won't let me set up a password and are blocking things obsessively, what is wrong with them?

They probably just want to keep you safe from the bad parts of the internet, but you should still be able to set a password for multiple reasons. When they aren't looking, press Ctrl + Alt + Delete, then click "Change Password," then fill in your old password (since you don't have one, leave it blank). Type in the password that you want into the new password boxes, then click "Change password." Explain to your parents that the password will protect your identity in case a burglar ever breaks in and steals the computer or a hacker tries to hack into it.