Host your own instance. I host my own GNU Social instance (which federates with Mastodon) and it is incredibly liberating.
It's a social networking site that I am in complete control over and feel safe visiting. There's also nobody tracking what I'm looking at or when I'm even online. Nobody will know whether or not I've read a particular post. Nobody can censor anything I say (not that I say anything that controversial), except maybe my server host (OVH), in which case I take all my data with me and move somewhere else. I'm not bound by any TOS. I write my own privacy policy (not literally---I don't have to worry about one). I own all of the data, and can do with it whatever I please. And it's free/libre software, so I can do with it as I please. (While it's free on other instances as well, as is Mastodon, you can't modify it; it's a SaaS issue).
I hosted my own Mastodon instance for a short time after it got popular, but there was a pretty big drawback. Each Mastodon instance is basically a community, where you can see other people talking and can even see a feed of the public toots from anywhere that other people on the instance have subscribed to. But when you host your own, there's no community, which makes it really hard to find new people to follow. So I basically stopped interacting with Mastodon after a week, because my feed was bare and I didn't have any good way of finding people.
That sucks. Mastodon tries to reduce the empty home page problem by automatically following the admin when you create an account, and by having a #followfriday hashtag where people post recommendations of who to follow, but that doesn't really help if you're hosting your own instance.
My recommendation would be to follow the admins of some of the more popular instances. You can find the admin on the about/more[0] page of their instance. They're usually interesting people, and can act as a gateway to finding more people when they reply to others or boost other people's posts.
@Gargron[1] from mastodon.social is always a good choice, as the creator of Mastodon and just being a pretty great person.
@Curator[2] from mastodon.art is great if you like art, they boost a bunch of artist's posts.
Other than those two admin recommendations, you might want to check out the admins of the instances listed at the bottom of the medium article.
I never had that problem. Sign up for a "regular" instance, and spend a little bit of time each day checking in, and you'll find people, and suddenly you won't have any problem not knowing who to follow once you've gone solo.
It's a social networking site that I am in complete control over and feel safe visiting. There's also nobody tracking what I'm looking at or when I'm even online. Nobody will know whether or not I've read a particular post. Nobody can censor anything I say (not that I say anything that controversial), except maybe my server host (OVH), in which case I take all my data with me and move somewhere else. I'm not bound by any TOS. I write my own privacy policy (not literally---I don't have to worry about one). I own all of the data, and can do with it whatever I please. And it's free/libre software, so I can do with it as I please. (While it's free on other instances as well, as is Mastodon, you can't modify it; it's a SaaS issue).