How to enable registration for Buddypress?

Yes, anyone can log in to a BuddyPress site if he/she is a registered member of that website by going to your-website-name/wp-admin

For Registering process, it entirely depends on the admin if he enabled the “Anyone can register” option from the Admin Dashboard.

If this option is checked, then users should see the Login/Register button or link on the website.

Update on March 17, 2020