Mispache basics
Welcome. Here is everything the site does, in the order you will probably want it.
Your page is yours. Go to your profile, hit the menu in the top right, then "Edit my page". That is raw HTML and CSS, rendered in a sandbox with scripts switched off. No scripts means nobody can run anything as you, and it also means your page is yours to break and fix at two in the morning. That is the fun part.
Your home page is a dashboard, not a feed. The widgets on it can be moved, removed and written. Click "Edit page" in the top right of your home page to rearrange them, and "Create new widget" to write your own in JavaScript. You are in charge of the algorithm here, because there isn't one. The Site Support box pays for the servers and cannot be removed. That is the whole deal.
Posts come in three kinds. Bulletins are short text, articles are longer and support markdown, and image posts are pictures with an optional caption. Every post has its own audience, and every post can have comments switched off.
Friends, pages and groups. Add people from their page. Groups are joined, pages are followed: same idea underneath, different default action. Businesses and meme pages live on the page side of that line.
Interests are how people find you and how you find groups. You will find yours on the Settings page, and every group's page shows its own as pills you can add to your list with one click. Adding one there is a good way to fill it in without thinking about it.
Invitations live on the Invitations page. Each link you make works once, and you can throw together a reusable link if you want to hand the site to a room full of people at once. You brought somebody in: the site will tell them so, and you get a friend request out of it.
Make it yours. Settings has eight themes and a palette you can pick apart colour by colour. None of it is permanent.
That is the tour. Post something.