"My life my choice" means that you get to make your own decisions about things that affect your life. This could be things like what you want to eat, where you want to live, who you want to be friends with, and what kind of job you want when you grow up. It's important to remember that while adults can help and guide you in making these decisions, ultimately it's up to you to decide what you want to do. Just like how you get to choose what toys to play with, you also get to choose what kind of life you want to live.