what do i do if i forgot my password to my macbook air

Hi,

Did you tried the "resetpassword" command via Terminal?

1. Restart your Mac.
2. While it is restarting, press and hold the Command + R keys until you see the Apple logo. 
3. Go to the Apple Menu at the top and click Utilities.
4. Then click Terminal.
5. Type “resetpassword” in the terminal window. 
6. Then hit Enter.
7. Type your password and a hint.
8. Finally, click Restart.

Hi there.

If you're unable to reset your password, try the methods listed here. I wish you good luck.

Good work :-))