recently i lost my iphone do you know some way to find cause i do not activate find my iphone

Sorry, see the following from If Find My iPhone or Find My iPad isn't enabled on your missing device - Apple Support

If your missing device doesn't appear in the Find My app or at iCloud.com/find, you didn't turn on Find My. There's no other Apple service that can find, track, or flag your device for you. But there are steps that you can take to help protect your data.

The rest of that support article has recommendations on some things you should do.