Hi Cheque2681,
Welcome to the Apple Community,
where some of us do our best to help each other troubleshoot :-)
Wondering if you have a back-up of any data on the phone that you may want to keep ?
Apple support have articles online that (1) outline the steps to unlock your iPhone,
and (2) get it ready for someone else to use:
If you forgot your iPhone passcode:
you need to use a computer to put your iPhone in recovery mode.
This process deletes your data and settings, including your passcode,
giving you access to set up your iPhone again.
https://support.apple.com/en-us/HT204306
You might like to check out this article:
What to do before you sell, give away, or trade in your iPhone, iPad or iPod touch:
https://support.apple.com/en-us/HT201351
And ... To Turn on and set up the iPhone again:
Turn on and set up iPhone:
(NB You can choose the iOS version at the top of the page, for accurate info)
https://support.apple.com/en-au/guide/iphone/iph1fd7e482f/ios
Hope this helps you :-)