I am assuming you will be shooting at a range, not your own property. If shooting at your property you would want target stands and targets.
You will need some ammo and it comes in two types, less expensive practice ammo and expensive self-defense rounds.
Get 9mm ball 115 grain ammo and don't get the cheapest stuff you can find. Expect to pay about $20 per box of 50.
Get a box of JHP jacketed hollow point self-defense ammo, $40 for a box of 50.
Get a device like a Magula to help you load your magazines, $25. It doesn't matter how strong you are you can damage the ligaments in your thumb putting in that last couple of rounds because the magazine springs are so stiff when they are new.
You will need at least two holsters but start with one. I prefer outside the waist band because it is so comfortable and can used for CCW or at the range.
I suggest getting a backpack BUG, bug-out bag, aka range bag to keep all your stuff in. Expect to find a nice one through Amazon for about $50
You will need a cleaning kit. You can find cleaning packages at the gun store. Those bore snakes are very popular. $25.
Hearing protection: DO NOT cheap out on ear muffs. The cheap ones will have thin plastic and WILL NOT protect your ears.
I use Howard Leight with the maximum 34 db protection, with electronics, $60. These are thicker and not as cool looking as the Sport models but my hearing is important to me. A 3 db difference between models is significant, it is a LOT more protection. If you don't care about the electronic models then expect to pay about half that.
I got a nice zippered hard case for $20 to keep the ear muffs in.
I use ear plugs and ear muffs together. The ear plugs will have the specs for noise reduction on the package and will cost about $5.
Get shooting glasses if you don't wear regular glasses. $10.
Optional: A gun belt is helpful at the range. It takes the load off your regular belt and can hold your mag pouches and holster. $25 from Amazon.
Optional: Mag pouches for your gunbelt, $12 from Amazon.
Optional: More magazines for a total of 3 minimum, I prefer factory mags. $30 each.