I can’t change restrictions because i forgot my password it was too old i can’t remember it

See If you forgot your Screen Time passcode https://support.apple.com/en-us/HT211021

If you are locked out of your Apple ID account you can go to https://iforgot.apple.com

This will provide you with the recovery steps you put in place for this situation.

Here are some support articles that should help:

If you forgot your Apple ID password - Apple Support

If you forgot the answers to your Apple ID security questions - Apple Support

If your Apple ID has been locked or disabled – Apple Support

If necessary, you will need to restore the device to factory settings. Do not restore from a backup made when the Screen Time code was active.

Restore to Factory setting.