I would suggest that you start off simple and come up with a weekly exercise plan, but be SMART about it. (Specific, Measurable, Attainable, Relevant, Time-Related) It can really help to zone in on what you would like to acheive.
Make your weekly training plan specific to your fitness goal, find a way to measure your progress and make the weekly plan. Be sure that it is something that you can do each week be relevant to the latest research and set a time that you will keep this programme.