You will start with "Scratch Online". It is a simple coding interface that allows you to create stories, games, and animations and share with others around the world.
Code.org offers a similar experience. Their vision is that every student in every school has the opportunity to learn computer science, just like biology, chemistry or algebra. Code.org provides the leading curriculum for K-12 computer science in the largest school districts in the United States and Code.org also organizes the annual Hour of Code campaign which has engaged 10% of all students in the world.