How to change Facebook “Add Friend” button to “Follow” button?
Generally when a new Facebook profile is created, the ‘Follow’ feature is disabled. This means that other Facebook users can only send you friend requests or personal messages in your inbox. Because of the default settings, no one can follow you, so no one will be able to receive your public posts as newsfeed in their timeline (all of your public posts will still be visible to any Facebook user who visits your profile).
If you already have lots of Facebook Friends who are more like potential clients, and you haven’t created any Page, then you can still add follow button so that your new friends can see your posts even if they aren’t in your friend list by following you.
You can simply add follow button following few steps but before you do that, it may be a good idea to double-check that only stuff that you really want to share with non-friends is public.