First of all I have to say that you don’t have a one. There is no such thing as purpose in your life. There are no specific things you have to do. You are absolutely free from everything. But later your mind get contaminated by the self-victimizing people around you. So you start thinking that there are things you are supposed to do in your life. You are who you think you are and you can do whatever you think you should do. Rules and obligations are none of your concerns. Those crap doesn’t even exist. They are just your delusions.
There is only one thing you should think of before doing anything. That is the prime truth of reality; the building block of all truths. That is causality. Whatever you do has its effects. So be mindful of your actions. Be mindful of your own thoughts and never mind the other things. When you stop being affected by other things you regain your freedom which you had when you came out of your mother’s womb. Don’t go and use it on doing things that would give you negative effects.
The affects you cause through your actions are the only thing that can define your actions. The effects could be all positive/all negative or mixed. Be aware of this and use your own understanding and reasoning to know your actions as good/bad/mixed. When doing this, don’t look at your actions from an outside vantage point. Your mind stands above all your actions. Be mindful of your mind. See what causes you to take various actions and what becomes out of your actions.
If the society, culture or your religion tries to give your life a purpose; just ignore those bullshit. If some motivational speaker tries this, stay out of his speeches. You have complete and absolute freedom to throw your life at any direction and change your direction. You are the one who’s gonna decide what you do with your life or somebody else will and you’ll live and die like those household appliances used, maintained and thrown away.
Just go out there and start doing whatever you want. Your actions will define what your life will be like. It could be total awesomeness or a completely miserable life. If you stay focused within and mindful of your actions and the causality, you will get whatever you want to get through your own mindful actions. Be your own god and take control over your actions. Decide your fate; create what you enjoy and live it.