Tools help, and because the Fediverse API is completely accessible, folks have already come up with awesome stuff.

• Populate your following list by finding friends, the Fedifinder still appears to work and helps find friends from Twitter on Masto: https://fedifinder.glitch.me/
• Now find friends of friends, the wider social graph. Followgraph works wonders: https://followgraph.vercel.app/
• Now you will likely miss posts, so try following updates of people if you really enjoy their content, plus of course pinning hashtags. PLUS. Up your game with an algorithm, either in the dedicated Mastodon app (trending posts) or with more customisation through the app Fediview: https://fediview.com/ Using Mastodon Digest (GitHub), you could also set up your own automation script.
• Folks have created lists and groups you can mass subscribe. The most successful one I know is from and for academics, perhaps there is a field for you in there. Journalists have similar stuff. See https://github.com/nathanlesage/academics-on-mastodon
• There are many awesome apps out there to access your content, improving the experience. I recommend Phanpy because of its unique and sleek design, see https://phanpy.social/. If you miss Quote Tweets and other stuff, try an app like Elk.
• Mastodon is only one option, if you want all of Twitter's tools and more cool stuff, try Firefish. You can migrate followers and posts. This way, you can skip many external tools.

And that's just the beginning.