Hi charlespanayot,
If you forgot your passcode and your iPhone says it's unavailable, you can try the steps in here first as it doesn't require using a computer If you see an iPhone or iPad unavailable message or Security Lockout screen.
If this doesn't work, you will need to use a computer and follow your related article If you forgot your iPhone passcode. When doing this, if the iPhone gets out of the recovery screen, don't cancel the download. Let the download finish, then try the steps again.
If it's the download that keeps stopping, make sure your Mac or iTunes on a PC is up to date and try again. If it continues, try using a different computer.
Check out this additional resource on YouTube from Apple Support with these steps: How to restore your iPhone if you forgot your passcode.
Take care.