A purpose statement is a simple one or two line statement about who you are. It should describe what particular talents you possess and the things you like about yourself. It's a simple thing but it helps when you are having a tough day or you are tempted to step off your chosen path.
You can start by simply writing down words that describe your strengths. Then make a statement about your purpose based on those words. This will be very general it's not supposed to be specific its a reminder for yourself of what you are about and what is important to you.
It's important to understand what talents you have because these are the very tools you are going to use to build your future. It's not good feeling bad about what you don't have (and let's face it most of us have a pretty clear idea of what we can't do).
When you start planning your future the talents and gifts you possess are going to be the way you get what you want. You may believe you only have one or two but most of us are far more talented than we will ever allow ourselves to believe.
It can be good to do this exercise with someone who knows you well. They will see in you what you can't see in yourself.
Remember that weaknesses are important to understand but they have no place in your purpose statement. You need to concentrate on what you do have.
What is you need some talent that you don't have? Well you are faced with a choice. Either you revise what you want out of life or you use what you do have to get what you need. For instance if you need to have a degree to do what you want to do then either you revise what you want or you use what you have to get the degree. What you have might be time or money or even just simple determination. There is usually a way to get through to something if you work hard enough at it.
However sometimes you just won't be able to make it. If you want to be a professional singer but you have no voice then you are unlikely to be able to get what you want. Often hard work will make up for a deficiency but when you can't you need to revise your plan.
Your purpose is important. It is the spring board for all the else that you will achieve. Over time it may change a little as you acquire new talents but you can only start with what you have today.
If you are a person of faith then your beliefs will shape your purpose. Think about what purpose God has given you and build that in to your statement.
Write it down.