Hi there! I am not a donor, but a caregiver of a kidney recipient, and mother of the donor. Rely on your caregiver at least the first 2 weeks. Our donor was so grateful to have someone to walk with many times a day, make her food as she had no interest, read to her, adjust those multiple pillows behind, and in front of, assist with getting to and from the bathroom/shower. Provide warm towels after showering, and being a good listener or silent companion. Everyone’s needs are different. Trust your caregiver, or get a new one if you feel uncomfortable asking for anything. Your are not a burden, you are a giver of life. Straighten your crown!
Bring your own music, short stories as initially it may be difficult to concentrate, stream some tv shows if you like. A short robe and very loose waisted pant, or drawstring pant will be helpful. Mayo will give you a large mug with straw for beverages. And that all important pillow!

I realize I have just rambled away here! Please excuse me! So, to answer your question on what to bring: very loose clothing, slipper socks, music/ reading material, and a fantastic caregiver. Oh, and halo polish. My very best wishes to you, now and always, and gratitude for saving a life.