By default, your personal profile on Facebook does not come with a Follow button, it comes with the Add Friend button. The Follow button has to be manually activated, and there are good reasons why you should. You've probably been on Facebook for at least a decade now, and in that time you must have had lots of Facebook friends who are more like potential customers or clients.
Facebook will limit you to just 5000 friends if you haven’t taken the time to create a business page, and you probably don't need to, because if you do, you will have to manually send a request to each of your friends to follow your new page!

Here’s how to turn on the Follow button on your personal profile:

On the mobile app, click on the menu option in the upper-right corner.
Go to Settings and expand.
Click on Privacy Settings tab.
Click and expand "Who can send you friend request".
There will be two options here. "Everyone" and "Friends of Friends". Select "Friends of Friends".
Click on the back icon to return to Settings.
Under the Privacy header, click on Public Posts.
Select the Public option under who can follow me, this will allow others to follow your public posts similar to the follow button on Instagram.

Enabling the Follow button makes your profile to look more professional and also offers these benefits:

After someone follows you, that person sees your Public updates in their News Feed. People may also discover your profile through the People to Follow box on the right side of their News Feed or through their friends’ News Feed stories.
Followers can share your Public posts, which broadcasts your post and profile to a larger audience.
You can have an unlimited number of followers (no more 5,000-friend limit).
You’re still able to block potential followers by adjusting your Privacy Settings Block List.
And you can connect with people on Facebook who prefer subscribing to a business page to liking it.
When your Follow button is open, anyone who requests to be your friend automatically becomes a follower unless you block them. You know they’re getting your public updates; you don’t have to friend them unless you want to also get their updates.
When you unfriend someone, they remain a follower unless you block them.
You can unfollow a friend. You are still friends, but you do not receive their updates in your News Feed.
Personal profiles get more exposure in the News Feed due to Facebook’s News Feed algorithm. You have a better chance of being seen if you’re also using your personal profile to post about your business.

See pics demo

https://africaexplained.com.ng/how-to-enable-the-follow-button-on-a-personal-facebook-profile/