I forgot my password for system preferences on my MacBook Air

Hi!

Assuming you are logged in with your Apple ID, you can reset your MacBook Air's password using that account. This should help:

https://support.apple.com/guide/mac-help/reset-your-mac-login-password-mh35902/mac

Reset Computer Password  for the Administrator Account Password

Intel Computer

1 - Restart computer and immediately hold Command + r keys

2 - Top Tool Bar >> Utilities >> Terminal

3 - Type resetpassword as one word and no spaces

4 - Press Return key

5 - Follow the prompts and remember the New Password

Apple Silicon M1 Computer 

1 - Choose Apple menu > > Shut Down.

2 - Press and hold the power button on your Mac until you see “Loading startup options.”

3 - Click Options, then click Continue. 

4 - Top Tool Bar >> Utilities >> Terminal

5 - Type resetpassword as one word and no spaces

6 - Press Return key

7 - Follow the prompts and remember the New Password