As you have to wear surgical stocking it's better to take slippers rather than flip flops.
I'm also having a Elcs on due date if baby doesn't come in the next few weeks due to Diabetes, and I remember first Emcs I couldn't sleep due to noise in the ward so ear plugs to drown out the noise and maybe eye mask if you like to sleep in darkness (although due to new born you may not get much sleep!)... If you get a seperate room then it will be much quieter.
It will be hard to move and bend and even get out of bed the first few days so things like loose fitting clothes that you can easily wear without moving too much... Tops with buttons to easily Bf if that's what you will be attempting. I've also bought a Feeding pillow to protect csection scar and support baby (not sure it will work but worth a shot) This time I've packed a mini suitcase with long handle as won't be able to bend to pick bag up if I need to get anything (last time I had to wait for hubby to do it)
I'm taking breast pads in case of leakage although last time I didn't have that problem... Also taking tummy band in case have to lift top to Bf so I'm not totally exposed on the ward
Your own sanitary pads although after c section I wasn't heavy at all so didn't have to bin any knickers but still taking some cheap primark knickers that I don't have to take home and wash as better then the disposable mothercare ones I had last time!
Hair grips, comb, wash bag with travel toiletries, hand towel
They won't let you get out of bed and remove catheter if your urine level and colour isn't what they expect so if you're not much of a water drinker take some squash to dilute.
Take soft tissues like Kleenex as I caught a cold before the Emcs last time and the paper there was horrible and nose became really sore (also Vaseline will help)
Maybe some snacks as you may miss food time like I did after the section so had to make do with a not so nice sandwich as the hospital canteen was closed by then and no nearby shops.
Other posters have mentioned all the other things so hope the above was useful!