Congrats on the purchase! Cycling is one of my favorite things to do. I think you're going to love it.
Couple things I would recommend - some kind of computer to measure speed and cadence. I have a cateye strada. There are more and less expensive options.
Small lights for the front and rear. These come in very handy when you lose track of time and are riding in the dark. These are cheap - around $10. These won't light up a path enough for you to see, they are just so the cars will see you. There are much brighter lights that work as headlights if you plan on riding at night.
An app to record your rides. I like map my ride, but strava is the most popular.
Maybe clipless pedals and shoes. They are scary at first, but become second nature very quickly. I can't imagine riding flat pedals anymore. But I only ride on the roads. Off-road, I may go flat
Post a pic or link of you bike!