how do i find my iphone 7 if Find My Phone was not on?

Well, if you have a another device (Ipad, mac book, etc) you can maybe in settings find it. If you don't find it, you might want to go to the place last time you had it. Or if you have Family Sharing

-Kingshow

By physically searching for it, posting notices around where it was lost, and if applicable, contacting the people running the place where it was lost.

(155828)

Legwork and phone calls