Just got a request about Facebook alternatives on the Fediverse.
There are a number of options, but the one most suitable for non-technical people is probably Friendica.
Friendica's major instances are already federating through ActivityPub (on the development branch of the code), such as:
https://nerdica.net
https://squeet.me
https://libranet.de
Friendica has a Facebook-like interface, and FB-like features such as events and photo albums.