Just make sure you have port 53 and 80 open. I recently had some problems myself trying to get Pi-Hole up and running. I already had dnsmasq taking up port 53 for a wifi hotspot, which conflicts with Pi-Hole’s own DNS. Aside from that, hosting any websites can also conflict with Pi-Hole’s frontend.
If you aren’t using your Pi 3 for anything yet then I already assume this shouldn’t be a problem though.
Good luck and have fun setting up your Pi-Hole!
Oder doch von der FAU?