Ok. Supposedly Maverick is no longer available to download according to some quick reading I did, so I'm not sure how you got it. I wouldn't recommend using it anyway. That's a very old version of OS X at this point and since you are just getting started with the ecosystem, you may as well start off with something more current, especially for the sake of security. Your Mac mini supports Mojave, the previous version of macOS, and Catalina, the current version. I would strongly recommend you consider upgrading to Mojave. Catalina would be fine too, but it's a bit harder to get used to since Apple really stepped up the security prompts on it.
Before I go further, what do you think you'd like to do? There are intermediate versions of OS X you can still get after Maverick (Sierra, High Sierra, then El Capitan), but again, for the sake of security updates, Mojave would be the minimum I would recommend.