A few questions and how to transition from treadmill to outdoor running.

First off, Hello, I hope to become a very active member of r/running and I am super excited to get back into running, but I have a few questions. First, how do I make the transition from treadmill to outdoor. Do I just start running outdoors? I just started back up from a 3 months hiatus and I am running a 5k in 28:11 on a treadmill, I have no idea how bad/good that is. I am 19 5' 9" 165lbs. A tad/bit overweight. Also I am wearing: Basketball shorts nike dri-fit shirt Nike lunar flys Regular ankle socks. What gear should I upgrade? Thanks so much, sorry for the long post.