As far as carbs go everyone is different. It really depends on how well your pancreas works and what meds you are on. I am only on metformin so I have to limit my carbs to 10-15 per meal, but others may be able to handle more. The way you figure it out is test before and 2 hours after meals. Ideally you don't want to go any higher than 120-140. If you do you know you are eating too many carbs. For myself to get my fastings under 100 my after meal numbers need to be 100-110, but that is just me. As far as calories, I never count but probalbly eat somewhere between 1600-2000 most days. Most of my calories come from fat like nuts, Coconut Oil, cheese and avacados.
As for exercise, I try to walk 3-5 miles most days. Now in this heat it is difficult and if I can't get out early I will do some exercise in side like light weights, weighted bars, push ups, sit ups and some yoga