A 'life plan' is a plan you have for how you want your life to turn out and how you're going to get there.
Think about a GPS. You know the destination you are trying to get to so you plug it into the system and start driving. You are driving with purpose, with a goal of exactly where you want to go. Without that final destination in mind, you just drive around aimlessly, with no direction, wasting gas and time, and getting lost. Eventually you will run out of gas and end up on the side of the road in a place you don't want to be.
Now just because you have a life plan, that doesn't mean it's set in concrete. Life is ever changing correct? Curve balls are thrown around all the time. But just like the GPS, when you take a wrong turn or there's an accident up ahead, it will reroute you and put you back on the path you had set out. During the detour you may see some beautiful new sites along the way. You may see something you wish you had never seen. You may learn never to take that wrong turn again. As long as you are clear on where you want to be at the end, you will always find your way back.
So a life plan is like a goal but on a grander scale. It's not just to lose 15lbs, it's what deep down in your heart you know what you want in life and how you are going to get it. I am a huge believer in growth and that we should always want to improve upon ourselves in some way or area of our life. I am very happy with my life right now, but I still have a life plan because there's so much more out there!
So start by writing down where you would like to end up. An example would be I want to live in Paris and own my own boutique of fine clothing, married, with 2 children. And then start planning how you are going to get there. Maybe you need to take a business ownership course or go back to school and get your degree. Maybe you need to ditch your dead-end relationship you are currently in so you are ready and open to finding the love of your life. Or maybe you are already married and need to have the 'baby talk' to your spouse. Maybe it's not to have kids right away but say in the next 3 years so you would like to start trying in 2 years. Maybe you would need to find a new job in retail so you understand how this type of business works.
Remember that a goal without a plan is just a wish. You have that end goal, now start planning and putting it into action. Ask yourself this question every day...
IS WHAT I'M DOING TODAY GETTING ME CLOSER TO WHAT I WANT TO BE DOING IN THE END.