Formulating a plan

Maybe fear is too strong a word for me to use.  I have to admit that I was unmotivated yet motivated at the same time.  I want to start off slow and them work my way up.  How do I formulate that plan, I am not sure.  I have things to consider such as my weight and my goals.  I also have to consider my goals due to my overall health and what I am physical able to do.  Well, I guess it is time to consider all these things and formulate a plan; if only I know how to actually formulate a plan.