I’ll provide a lot of resources for more info, but basically and most simply, you own your body because you have a better claim to it than anyone else.
See:
“How We Come to Own Ourselves”
“The Economics of Self-Ownership”
“Argumentation and Self-Ownership”
“Self-Ownership, World-Ownership, and Initial Acquisition”
“The A Priori of Ownership : Kant on Property”
“Private Property’s Philosopher”
Hoppe in One Lesson, Illustrated in Welfare Economics
Be sure to check out The Economics and Ethics of Private Property and The Philosophy of Ownership
And as for your question about rights, it is addressed in the texts above, but also you might check this playlist. (If you’d like all the Tom Woods lecture one page, it was posted here.) Also check out selected parts of The Ethics of Liberty and A Theory of Socialism and Capitalism (such as chapter 15 and chapter 2, respectively)