I found one of my families old iPhone nine and I turned it on and it was disabled so I didn’t answer on how to reenable the iPhone nine with my computer because every time I try it won’t connect. It’s very annoying.
Apple never sold a model called an iPhone nine. Please check again to see what model of iPhone that you have.
Do you have a complete recent backup of the iPhone's data on iCloud or a computer?
If yes, you can use the backup to restore data back to the phone.
If you have no backup, there is no data to restore.
There is no such version as an iPhone 9.
Restore your iPhone, iPad, or iPod touch from a backup - Apple Support
How to Restore iPhone nine after data erased
