A good thing to do is to look up hashtags. As Mastodon’s full text searching is opt-in, (for privacy) it can be hard to find people how one might be used to on other social media. So try like, # privacy or # techlore and see what pops up. You can also follow hashtags or add them into lists if you want to follow that and get a wider net of posts to see.
You did the hardest part, (picking and signing up on an instance,) and now you’re at the second hardest. Finding people to follow to make it worthwhile.
::EDIT:: Oh! Also, Fedi Follows is a great resource for people starting out. They have a lot of accounts grouped up that could be of interest.
Fedi Tips is also good for general information.
Good luck! <3