Begin by creating a timeline in your mind. Mark the major milestones in your life such as birthdays, graduations, and moving to a new place. Then, pick the earliest one on that timeline. For instance, if your birth is the starting point, you can talk about how your family reacted when you were born, the environment you were born into, and any stories your parents told you about that time. This way, you can gradually unfold your life story.
To start telling your life story, think about what has had the most impact on you. It could be a relationship, a job, or a personal achievement. Begin with introducing this important aspect. Say something like 'My life has been greatly influenced by my decision to pursue my passion for art. It all started when I was very young...' and then go on to explain the details.