How long will you be an inpatient?
I don't mean this to sound negative so much as practical but I have health issues and have been in for quite involved surgeries quite a few times. For the mostpart in recovery afterwards I've not wanted to do anything and have felt rough or a bit sick from pain relief and so on, so it's mostly been about comfort and convenience - comfortable clothing and lots of spares - bearing in mind where any stitches might be and where the clothing hits or how it comes on and off, extra long charging cables, wireless earphones, a soft blanket, slippers you don't mind getting dirty, body and face wipes, hair clips, dry shampoo, lip balm, hand sanitiser and hand cream, a refillable water bottle like a Chilly's that will keep things cool/hot.
Food wise it's best to opt for plain things, the sort of thing you usually fancy when unwell. I always take ginger biscuits, plain flapjacks, chocolate digestives to have with a tea, boiled sweets and mints (nice when you want to freshen your breath but can't brush your teeth at the time). Friends and Family can always drop off something else if you fancy it.
I would take as little as you reasonably need and nothing with strong fragrances or allergens as ultimately unless you are in a private room there will be other people nearby who may not want to smell those things, or for whom there are allergens.
Last time I went in I treated myself to a lovely soft blanket, a couple of new books, an audible subscription, foot cream and some good earplugs.
Best wishes for your surgery and recovery OP.