Basic use you aren't going to break it. The microsd card can be reformatted if anything goes wrong. It's not until you start messing with the GPIO pins that you could mess something up.
A good first step if you weren't familiar with it, install any Linux distro that's supported that looks appealing. If you already know how to use Linux you can move onto making your own VPN, a PiHole as suggested above, DNS caching server, retro emulator.
Tons of options, but they all hinge on basic Linux knowledge.