Mastodon was created by coders, which means most other people will not understand what’s going on with the site. No one pictured an eventuality like this (Faulknerian idiot man-child purchases Twitter, opens the gates for slavering bigots and domestic terrorists, fires all crucial operational staff and oversight, blames leftists for plummeting market performance, then threatens companies that advertise on Twitter), so it’s not necessarily accessible to anyone but the most rapacious autodidacts.
So many people have tried to explain this in so many ways, I know. I’ve explained it, refined my understanding and corrected my explanations, and attempted it a few more times. This is one more shot at explaining the barest fundamentals of communicating within Mastodon and finding your friends.
The first thing you do when you login to Mastodon is choose a server (or “instance”). This won’t mean anything to you at first, because there’s hundreds of servers. (If you’re curious: some individual is fronting the cost for that server, and some servers have themes, like they’re all code monkeys, or they’re knitters, or they’re into anime/manga. Other servers are just up and running for the sake of granting people access to Mastodon.)
You’ll probably find popular, generic-use servers like @mastodon.social, @msdtn.social, @mastodon.online, @mastodon.sdf.org, and so on and so forth. It really doesn’t matter which server you choose, and if you develop a preference later, you can migrate to another server.
Along with the server, you’ll have to choose an ID for yourself. I chose “cwwilkie” like it was on Twitter, and my server is @mastodon.social. This is important for finding your friends, especially if you’re not on the same server. In the upper left of your screen is the search bar, and you have to enter your friend’s information like this: @USERNAME@SERVER
In my case, you’d run a search for @firstname.lastname@example.org, and no matter what server you’re on, you can find me and follow me (add me as a contact). It’s best to search for someone this way, and here’s why: if someone gives you the URL for their profile, it puts those elements in the wrong order. If you search for them in that order, you won’t find them. If you go to their profile page and try to follow/add them, and they’re on a different server, the program will require you to create a new account on that server. This is unnecessary! You can find and connect with all your friends, no matter what server they’re on, by using the arrangement I described above.
When you’re on Mastodon, you have some channels in the right sidebar: Home, Notification, Explore, Local, etc. These behave as filters that only allow certain messages through. You know what notifications are: this is the update of everyone who’s liked your posts, boosted (retweeted) them, everyone who’s following you, etc.
What you want to know are three ways to filter all the messages out there. HOME is all the posts from the people you follow, only the messages from the people you want to read. LOCAL shows you all the messages of everyone on your server. You may not know these people, but many servers are bound by a theme or interest, so people will still want to congregate and meet new users with something in common. FEDERATED means every post, everywhere, on the Mastodon network. You can look at that if you’re bored and curious, I guess, but if you’re just here to talk with your friends, ignore Local and Federated. Stick with Home.
Think of it like this crappy AI-generated illustration: you are an astronaut in a sky full of planets. The server you signed up with is a planet. But you also have a cell phone, filled with your contacts, and there’s also the rest of the universe out there. Your cell phone is HOME, where you talk to everyone you know. The planet you’re on is LOCAL, where you can chat with everyone else on that planet. The rest of the universe is FEDERATED. Who knows what’s out there.
After that… hashtags seem to be more utile than on Twitter. That’s really how you flag attention and find people with shared interests, so try out hashtags for a while. That’s all the advice I’ve got.
Now you know how to find your contacts and how to only see what they’re posting. Armed with this information, you can make Mastodon perform like a pared-down, ad-less Twitter for you.
I really hope this makes Mastodon more accessible for you. Please let me know if you have any questions, so I can refine this guide down further.