I don't have a apple account I bought a I phone from my friend but don't know passcode

Your friend needs to thoroughly cleanse this iPhone as follows:

What to do before you sell, give away or trade in your iPhone, iPad or iPod touch – Apple Support

If that is not done, you may have far more serious problems than a passcode. The iPhone may be Activation Locked, in which case you can never use it.

Hopefully your “friend” is friendly😊

Hi there,

As long as your friend has signed out of iCloud, then you can follow this guide to restore the phone and set it up: https://support.apple.com/en-gb/HT201252

LW78