Well, first of all, air is free and is not only valuable, but, if you don't have it, you will die.
Another thing that is free and is essential for living is, friendship. Think about your friends. If you have friends like I do, you cherish, appreciate, respect and are grateful for them. They are always there for you, especially true and loyal friends.
What else is free? Well, family. I love my family. We have great relationships. We don't argue or fight. We get along very well. I love them. I cherish every conversation I have with them. I appreciate their advice when I ask for it. I appreciate their silence when I don't ask. I appreciate their support and love for me.
Education is free. You can study at the library and pursue your own personal education for free. You might have to pay to go to a high school or college in China, but, you can always go to the library and learn, for free.
There are so many things that are free. I give a lot of things away that can and will change your life. I give free English lessons. I give away free books that I've written. I give my time and efforts at an English corner where I help others learn English better.