iPhone erasing
I had the 10r and erased everything so I can give it to a friend but I didn’t sign out of my iCloud prior, will it do it automatically when I erase the iPhone?
iPhone 11
No. See the following for instructions: What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support
There is a section for what to do if you no longer have the phone.