Don't be too reliant on the diabetic nurse or dietician. In my experience (been type 2 for 20 years), they're not that helpful and offer conflicting advice. One told me to eat little and often, the other told me to have fewer big meals - so what the hell are you supposed to do? As said above, far better to test, test, test and explore what works best for you. Re testing, you'll probably get conflicting advice on that too - one of my nurses said you test yourself a couple of hours after a meal to see how it affected you - another said to test just before eating to see the longer term effects of the last 2/3 meals. The GP said not to test too much and it's better to rely on the 6 monthly HBa1c tests. Like I said, be prepared for conflicting advice.
Until you have your first appointments and get your test kit, you can do some pretty simple/easy things though. First is to cut out all the stuff that is clearly bad for diabetics, such as sugar in hot drinks, sugary breakfast cereals, chocolate, biscuits, sugary fizzy drinks, alcohol, white bread, fast food/takeaways etc. Start eating more fruit, veg, salad, lean meats, etc. Start taking more notice of the traffic light colour codings on the food you buy and avoid anything at all with any red boxes!
Also start thinking about portion size and reducing what you eat. Even if you're eating healthy things, you really don't need a huge plateful! Train your body/stomach to expect smaller portions.
When you get into a proper regime, hopefully with some good advice from the NHS professionals, you can then "fine tune" and discover what works for you and what you should avoid and you can then think about finding suitable alternatives, i.e. lower sugar alcoholic drinks, lower sugar takeaways etc.
Don't expect instant results and don't expect it to be easy.