My cholesterol is high but the ratio is good. Should I consider a statin or is it ok to do nothing? Which statin and why?

More info needed. The use of statins (or any other medications) depends on many factors, such as family history, other medical problems, current state of health, other risk factors, etc. It also depends on your exact ratio vs. "a low ratio". Discuss this with your doctor.
Not yet. Change in lifestyle and diet may be all you need to do. Low fat, low cholesterol, less meat will help. Things like 1/2 tsp cinnamon and honey can help as well.