Which should I manage more, post-meal blood sugar or fasting blood sugar?

I'm not too worried about my blood sugar yet, but it keeps bothering me, so I'm really worried.

My doctor told me that if my fasting blood sugar hovers around 120, I am in the pre-diabetic stage.

Now I am looking for a more systematic and scientific method.

I recently saw on a medical program that it is important to manage not only blood sugar but also blood pressure and cholesterol.

I hear that managing blood sugar and blood circulation simultaneously through a method called blood glucose therapy is effective.

I would also like to know about diets and lifestyle habits that help manage fasting blood sugar.