Our purpose in life - I'm talking about what we 'think' and 'believe' to be our purpose at the time - changes over time. As youngsters our purpose is to get out there and experience the big, wide world, to realize our dreams of adventure. Later, our purpose might be to find the girl (or boy) of our dreams and to give and receive plenty of love of the romantic kind.
As we age our purpose often becomes more diffuse, more nebulous, but it generally gets down to become more aware of what and who we are. This is if we're sensitive enough to our own needs to realize this; overwise we might lose ourselves in and endless and disatisfactory chase after 'grown up toys,' and drawing attention to ourselves.
When we're able to ask ourself a question like, "What is the purpose of my life?" as you have here, we're on the road to self-understanding, self-actualizaiton and, hopefully Self-realization. Oh, and once the journey has begun it seems there is no going back.
Purpose in life ...I think it is different for everyone. One purpose is to be a good person, treat people well and find joy in things you do. We all have daily challenges and have to live with difficult issues. If you are a parent a purpose is to bring up a good child. If you have a job do your best. Always strive for your personal best and don't be swayed by other's accomplishments. We all have a different path and journey.