The hardest part will be being away from your family, so make sure any other children understand that you may be gone for a few days in a worst case scenario.
Make sure your older kids will be able to climb in/out of things without you having to lift them. If they get hurt and need a hug, just get down on the floor with them.
Everything for hospital in a suitcase sort of bag that you can keep on the bed with you so you can reach everything. Lots of nappy bags and a small/disposable changing mat, and a little tupperware box of water if you are not using wipes at first, so you can change nappies from your hospital bed. Very long charger cable.
Get yourself walking around the hospital as soon as you can.
Pack yourself some packed lunch type meals, loads of snacks and a massive water bottle that won't leak. No one can bring you extra food right now.
Have a spare bag packed with more clothes and nappies, in case you end up staying longer than you need.
Look up the rugby ball hold if you are planning to breastfeed. If you are separated from the baby afterwards (if baby needs some extra help and you are not yet able to get out of bed to visit) insist that someone helps you express colostrum and takes it to the baby. Insist on your right to feed your baby and get someone to wheel you to the baby ward to visit if necessary.
Start laying in a supply of paracetamol and ibuprofen. You will need to take two of each every 4-6 hours for a week or two and shops won't let you buy much in one go.
Do not lift heavy things. Do not exercise beyond daily chores until 6 weeks. Nothing more than long walks for 10 weeks and wait until about 6 months before running. Honestly more like a year before serious high impact exercise.
Massive knickers to go over your scar. Slip on shoes. Comfy trousers.
Buy some good toys and hide them in reserve for days when you and the baby just need to feed/rest.
Batch cook while you can.
Oh and enjoy picking up your older children and giving them a big hug. It will be a little while before you can do it again, but the time will fly. Good luck 