I just found this article on how to create a basic ActivityPub server. It let's me think about adding ActivityPub support to my hugo-micropub project (which then becomes more than just a Micropub endpoint for my Hugo setup). It's definitely a project I finally want start once I'm done with this semester. I still need to think about whether or not to ignore inbox queries and if yes, how to handle them?
I started my fediverse journey with Mastodon, the most popular fediverse / ActivityPub software out there. First I joined a public instance, then I temporarily hosted my own instance, forgot about the fediverse, joined again on a public instance some months later and eventually settled with my own Pleroma instance, which is now running for almost a year. But why shouldn't I take a look at other options too? Some months ago, I briefly tried Microblog.