Can I get my old iPhone password without connecting it without a computer

If you mean the Lock Screen passcode, you can’t get it even if you do have a computer. You will have to erase and restore the phone.

Follow the instructions here: If you forgot your iPhone passcode - Apple Support

no

if you do not own a computer then you need to use the computer of a

friend/relative/public library or computer store

Hello ~ It depends…take a look at the link below by clicking on…

If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support

More than likely you w need the use of a computer though. Take care.

~Katana-San~