On my i phone 7 i forgot my pin how can i change it or get in without a computer i dont have my computer anymore

if you're on iOS 15.2 or later, might be able to do it without

How to remove your iPhone, iPad, or iPod touch passcode without a computer - Apple Support

but you may need a computer, in which case you'd have to borrow one or head into an Apple Store

You can visit your local Apple Store to see if they can help.