Hello and welcome.
I don't know why health professionals keep talking about sugars when it comes to prediabetes and diabetes, it constantly baffles me. The letter for my diabetes training sessions, provided by the NHS, recommended I consider "reducing boiled sweets and sugary fizzy drinks".
For the avoidance of any doubt, it's all carbohydrates that affect blood glucose levels. Starches and sugars break down into glucose during digestion. So higher carb items include breads, pasta, rice, potatoes, beans, legumes, most fruits....plus all the sugary stuff you've already heard about. Doesn't matter if these are wholewheat, wholegrain, brown or white, they're all carbohydrate rich. That's not to say some don't have beneficial qualities to health, but for blood glucose levels and those with insulin resistance, they're what cause the most problems.
The advice you've received above from others is really good, sound advice. Stick around here, it's helped me so much in the last 5 weeks since my type 2 diabetes diagnosis. The people here are lovely, knowledgeable, and there's so much that can be gained from their experience. You're only prediabetic currently, so you can turn this around. You can do it, don't sell yourself short. Loads of resources and posts on here for various diets, recipes, and general approaches for both prediabetes and diabetes management generally. Have a look around and don't be scared to ask questions!