@anchel absolutely. Though selecting an instance is not that important as you can change to another quite easily. And compared to 5 years ago when I first tried it, there are now a lot more of explanations online, starting with the Mastodon official site. Accounts like @feditips are also quite valuable to learn about the way it works.

@BeckePhysics It could be that mastodon.social is saturating. it happens a lot these days. try again a bit later. Yesterday I had to try for a little while before I managed to log in. I think I’ll migrate to another less populated server to avoid this.

@anchel You don’t need to create separate accounts. you can look for anyone on any instance in the search tab. Once you follow them, you’ll see their posts in your timeline.
Now, on a more technical level, when a new instance start, it is isolated and you can only see people from your instance. Each time a user follows someone from another instance, a link is created and you’ll be able to see every post from this instance in the Federated tab. With time instances get more and more intertwined.