Trainers fitted at a Runners Need/Up and Running/local running shop. Get some specialist socks too, massively reduces chance of blisters.
SweatyBetty Power shorts or leggings, phone pocket down your leg, zip pocket for keys on the back. We have a “runner” key that lives on a hook so we don’t end up carrying bunches.
Underwear- anything that’s comfortable but think about the movement angle… chaffing from lace is not something you need. 5 back of bog standard plain elastic briefs/seam free from M&S does the job for me.
Sports bra - THAT FITS!!!! I see so many women running with everything jiggling around and for me that would be so painful. Also can chafe if not correctly fitted.
Cap/Hats etc- your choice.
Sunglasses- Goodr is the “cool” brand at all my local races, the brighter the better! And only £30, they never slip.
Don’t forget SPF or you might find yourself with some cracking tan lines from lengthy time outside!
Don’t expect too much of yourself too soon and celebrate all your milestones (first km, mile, 5km, first time running 30min non stop etc!)