You don't have any kind of diabetes yet and so you could possibly put off the fatal day by (for example) giving up sugar and things with sugar in completely. No fizzy drinks, sugar in tea, or cakes. Cutting down on things with flour in is a good thing too but maybe you don't have to worry too much about that yet.
Those of us with type 2 usually can't eat bread or cakes at all but I doubt you need to panic yet.
The simplest and most effective exercise is walking. It lowers the blood sugar level quite effectively. I prefer not to have static exercise machines in the house since it is too easy to get off them and fall onto the sofa.
There you go. somewhere to begin.