Hi and welcome
Wow, I am impressed. You must have a forward thinking GP practice to be recommending low carb, higher fat (LCHF) diet. Most are still stuck in recommending the low fat "healthy eating plate" guidance, even for us diabetics, which can set people back.
It is strange when we have spent our whole lives being told that fat is bad and makes you fat and gives you heart disease, but there is a growing wave of modern scientific thinking that this advice was based on flawed research 70years ago and in fact the low fat way of eating may be partly responsible for the surge in people being diagnosed with diabetes now. If you remove most of the fat from products they don't taste very good, so sugar was added to make them more pleasant to eat and the more sugar you eat, the more you want, whereas fat takes longer to digest and therefore keeps you fuller for longer, so you are less likely to over eat.
Learning how to eat low carb and higher fat takes time as it is pretty alien to most of us, but once you get your head around it, it is a very enjoyable way to eat. I was a serious sugar addict pre diagnosis and I also ate lots of bread and potatoes and pasta, albeit wholemeal varieties. I love the fact that I no longer crave sugar or even carbs that much. I almost never eat bread (maybe once a month if I go out for a meal) and I just eat a small portion of potatoes once or twice a week and even more rarely do I eat pasta, even the wholemeal variety spikes my BG for 8-10hrs and balancing it with insulin is very difficult. I was never keen on rice so I don't bother with that at all.
I enjoy cream in my morning coffee and I treat myself to a chunk of nice cheese at least once a day and I cook leafy green veg with a good knob of butter or dollop of cream cheese and cauliflower cheese or mashed cauli with cream cheese is a yummy staple of my menu. I have always enjoyed fatty meat like lamb chops and belly pork, so I can eat those guilt free these days and oily fish like salmon and mackerel are good and plenty of nuts and eggs (I have my own chickens) and salad with coleslaw and avocado, and ratatouille made with lots of lovely olive oil. These are all ways of increasing fat intake.
For info, Lidl do a really nice litre bucket of Creamy Natural Greek Yoghurt which is the lowest carb yoghurt I have found so far and many of us have it with a few berries like raspberries and strawberries for a dessert or as breakfast..... And Nature Valley Salted Caramel Protein Bars (just under 10g carbs per bar) or Aldi Gluten Free Nut Bars (5.9g carbs per bar) both of which come in a 4 pack are firm favourites here with low carbing members of the forum, if you fancy a sweet and satisfying treat occasionally. You will get used to reading the carb content on the back of labels and be able to quote the carb content of foods off the top of your head after a while. Once you figure out a basic shopping list of low carb foods, the whole process becomes a lot easier.
Anyway, that's just a few tips to help you get started. Since you are just pre-diabetic (HbA1c of 42-47) you should manage to push your HbA1c back into the normal range with minimal changes, whereas some of us needed to take a much more radical approach (My HbA1c at diagnosis was 112 so I had to be pretty strict)
Increasing your level of activity is also important and a good brisk 10-15min walk every day is as good as anything, so don't feel like you have to do anything too exertive, unless you are already pretty fit and doing more.
Good luck and keep us posted with your progress and ask whatever questions you have. Most of them will have cropped up at some point and we have a wealth of friendly, knowledgeable and experienced people here on the forum to answer them.