Some odds and ends you'll need sooner or later depending how you ride:
water bottlle, as others mentioned maybe a priority
tire patch kit
floor pump
multi tool
bar bag or under saddle bag to carry tools, snack
tail light
headlight (I seldom use mine, but I do get caught out at dusk occasionally.)
A pleasant voice to announce "On your left"

you don't need all that now. Take some time to get comfortable on the bike. I just rode the neighborhood first year I got mine.then got a car rack and drove out to uncrowded roads. It was years before I bothered with a jersey or padded shorts, though I ride longer now and appreciate them.

good luck and enjoy.