I would not advise ordering Protein prior to surgery. My tastes completely changed after my surgery. I have six huge containers of Protein powder and I can only stomach two of them now. Everybody has a personal experience of their own, so don't quote me on any of this, haha! It's much more important to get your fluids in when you are newly post-op, so stock up on SF Jello, popsicles, etc. Try protein carefully as you are allowed, but get ready for really small portions.
You won't need much at the hospital, but have some chapstick ready. I was catered to like a princess, so I only needed loose, comfortable clothing and my own pillow for the trip home. I hope you're treated as well as I was.
Just remember why you are doing this and follow your surgeon's guidelines strictly. They know how to keep you safe and healthy. Best wishes to you on your journey!!