Welcome to the forum.
As Mark said up there, as well as sugar, carbs are the thing to look out for. White, starchy carbs are bad for us. Some of us find that wholemeal versions can be better to tolerate; fibre slows down the absorption of glucose into the blood which is preferable. Vegetables have carbs in, but they're generally good for you so eat those, just be aware that underground veg, such as parsnips, carrots etc can be higher in carbs than others. Meat is generally zero carb, and often has protein in it, which is good to have when you're cutting down your carbs as it replaces the energy you lose from the carbs. Watch out for sausages, as they can sometimes have a few grams of carbs in, so the higher meat content the better. Fat containing foods can be ok too, things like milk will contain lactose which can raise your blood glucose levels, but in moderation can be fine, and obviously will still give you your calcium and all that for the day. Fat can also slow down the absorption of glucose into the blood.
I would recommend looking at portion sizes as well. Before diagnosis, my portion sizes were huge in comparison to what they should be. I always look at the recommended serving sizes on food now and eat to that. It took a fair while to get used to my food disappearing, but it makes keeping track of my food so much easier, and also it's better for my weight and control. I keep a food diary too, so I can keep a note of what works for me.
One thing I've discovered is that we're all different in how the food affects us and what we can tolerate. You might find that you can eat rice without much of a rise, whereas another of us couldn't. It's all about testing to see what works for you. It's a marathon, not a sprint (a phrase I dislike but is very apt here), and it's worth taking the time to get used to it.
The forum is great if you have questions 🙂