Hello and welcome. You are in the right place here, and with a family history of diabetes, are hopefully better prepared than the people whose diagnosis comes out of the blue.
I suggest you work through the Learning Zone, for the best way forward for a pre diabetic. I am reluctant to say "should and shouldn't eat" as every person's body is different, and reacts differently to various foods. I prefer to say "be mindful of what you are eating, and in moderation with high carb foods". Current thinking is to follow a reduced carb diet, the suggested amount being less than 130gm per day in total (food, drink, snacks, treats). This does not mean NO carbs - in fact that's virtually impossible as even the humble lettuce has carbs. As you are pre diabetic and need to lose weight, a few tweaks to your lifestyle should hopefully do the trick. I had to experiment to find out what carb level suited me, and now aim for 75-90gm a day. But I am full blown Type 2. Some people are more sensitive to carbs, so have less, and others can eat more.
The first thing to do is start a totally honest intake diary - food, drink, snacks. The foods to look out for are bread, potato, rice, pasta, cereals, many fruits, processed foods, plus of course cakes, biscuits, sweets, pastries. Brown versions have just as many carbs as white versions, but may be slower acting. The way to find out which foods affect you is by testing, immediately before and 2 hours after first bite, to see how your blood glucose rises. You would have to fund a glucose monitor and strips yourself. (Others will make suggestions). I also got an app which keeps my food diary for me (easier than working out each item), and measures amongst other things, calories and carbs. That way you will soon work out which foods affect you and which do not.
I tested for a few weeks to get the idea, and now I just test for new foods. For example, I can eat a couple of new potatoes, or a medium slice of no sugar added wholemeal bread from a 400gm loaf. But I can't take rice, pasta or strangely, apples! Instead I look for substitutes, such as cauliflower rice/mash, roasted squash wedges, black bean pasta, courgetti. The forum Food/carb queries and recipes will give you lots of ideas.
5 years into my journey I still plan my daily food and keep the diary. I have found lots of different foods and enjoy experimenting. My slow cooker is my new best friend. I also went back to the swimming pool after more than 50 years, and now do 2/3 aquafit classes a week. I know others who cycle, or do classes like yoga or pilates. Even a daily walk is good for you, dog optional.
Best wishes