Misskey, Calckey, Pleroma, Mastodon- All perform the same essential function. Microblogging (with minor differences e.g Pleroma has a 5000 word limit per post) Think Twitter.
Pixelfed is an image sharing platform - Think Instagram.
Friendica will give you a similar experience to Facebook (Macroblogging)
None of those platforms have real messaging (Direct messages, but not private or encrypted)