I hope you find the course informative as it sounds as if you didn't get ay support in making some lifestyle changes when you had the prediabetes diagnosis. That is a shame as it could have prevented your progression to a Type 2 diagnosis. Hopefully it has now been picked up before you are too far into the zone.
Have a look at this link as it has good explanation and give you some ideas for modifying your diet
https://lowcarbfreshwell.com/ This program was developed by a GP practice who found the standard NHS advice based on the Eat Well Plate did not work for their Type 2 patients as it is too high in carbohydrates.
You may then find it raises questions for when you do the course.