where to start?

I just bought this and been going through the different things offered but would like more specific help based on my current needs. I am a medical student and would like to know how to better manage my time. Sometimes even when I know what I need to do and have a plan to accomplish it I kinda put it off for a few moments before I go and do it. I would like to just be able to do the things that I need to do without dragging. What can I do to solve this?