Try not to stress, prediabetes and diabetes type 2 take a long time to develop and the good news is that both can often be kept under control or even put into remission mostly by keeping to a low carb diet, but that too takes time and quite a bit of getting used to.
No rush, no panic, it's a marathon not a sprint.
At prediabetes levels you have time to learn, and there is a LOT to learn so just start reading around.
Expect some confusion, some errors, some misleading advice from some professionals along the way but you will get there.
Read around the forum and don't be afraid to ask. We all started somewhere, most of us in shock and dismay