What do I do if my old iPhone says connect to iTunes to reset passcode to unlock iPhone

You can try to reset the passcode by using the Apple Support document linked above your name, but there might be a reason why the messages that you are seeing instruct to connect to iTunes (on a PC) or the Finder (on a Mac).

If you cannot reset things using the first support article, then you will need to use this article:

If you forgot your iPhone passcode - Apple Support

If you have a current backup, you can use that during the new setup process to restore data to the phone.

I don’t have access to a computer to hook up to iTunes is there another way I can unlock my iPhone 6S

No. You will have to visit a friend with a computer or an Apple (or other tech) store and use one of their computers.