Minimal valuables, I'd take wired headphones if compatible with whatever divice you use? If you're a bit loopy from meds airpods are very small and easy to misplace.
They also have a habit of whipping sheets off beds at a moments notice, I'd be worried something little like that would end up going through the laundry. They managed to run off with a woman's pajamas she'd left on the bed while she cleaned her teeth last time I was in hospital!
I would absolutely take eye mask and ear plugs, absolute necessity.
Hand cream and face moisturiser is nice, I always find my skin goes painfully dry.
Some way of entertaining yourself, book, phone with streaming app, something like that. Charger. Minimal cash, in case you want some sweets or something and are well enough to go to a vending machine or cafe/shop.
Overnight basic toiletries. You'll probably be feeling like doing the absolute minimum. Dry shampoo if your hair will really bother you in case you can't shower?
In my experience when you have surgery your belongings are locked in a locker, and they attach the key to your gown, that you're wearing while you're under. Once you're in recovery, you give someone the key and they go and get your stuff for you.