Either way, that requires a healthy Facebook friends list. You can correct it, of course, but even this is accomplished by selecting the correct person from your Facebook friends list. Let's go over the features that integrate with Facebook: by default, the app scans photos with facial recognition to suggest who you should tag in a given photo. The app was first created as a replace for Facebook's own synchronized photos, and even today, it functions at its best (some would say at all) with the Facebook app installed and a healthy friends list. There's no bones about it: Moments is made to be used with Facebook. You can't even crop photos, or frame them, like you might in other photo apps. The only problem is that there's no way to edit photos.
Regardless of what you're doing with it, it's easy to use.
The app actually does this automatically, by who's in them and where they were taken, but you can fine-tune things a bit more if that suits your fancy. Sharing is easy: just select a Facebook friend and it'll reach them via Messenger.