Hi there
That’s great to hear that your parents have agreed to have him neutered and that you have found a vet who feels confident to do the surgery. As you have mentioned, keep food and water available before surgery, it’s also a good idea to take some hay or pellets with to the vet that Jumpy is used to eating so that they can offer his food to him after he wakes up from surgery. Some clinics don’t like to send rabbits home until they have started eating again, so it’s good to have a food he is familiar with and you know he really likes.
You’ll need to keep him confined after surgery, soft bedding, and nothing he can jump up onto which can cause ripped stitches. Rabbits can’t regulate their body temperature after surgery so they can get too cold, keep an eye out for this as you may need to wrap Jumpy up in a blanket and hold a warm water bottle or heat pack against the outside of the blanket for short periods of time (not too long as overheating is a risk too). Problems post surgery seem to be more common with females as the surgery is more invasive, but can certainly happen with males too. Just make sure he is eating and pooping, he may take a while to poop even after eating as his gut will have slowed down from the anaesthetic. Make sure the vet prescribes a rabbit safe pain killer as well which will help take the edge off and help his appetite etc.