Welcome! I'm not from the UK, but just vacationed there (Scotland) and it was pretty amazing!
Some of my pre-op prep was:
Stop drinking fluids while eating meals, wait 30 min after eating to drink
Learn to eat in smaller bites by using baby spoons/forks
Stop carbonated drinks and caffeine (I weaned off coffee before surgery to prevent the caffeine withdrawal headache while in the hospital, plus my doc wants all his patients to be caffeine free for at least 6 months after surgery)
And I started using the myfitnesspal app to track my food and fluids and still use it now, it's a big help