I want to move to Linux Mint without losing data, can someone help?
The most important thing to do is backup your data to an external drive. Unless you are planning on dual booting (much more complicated) you will be wiping out the entire drive that has windows on it when you install Linux.
This guide goes through the whole installation process.
I would argue the point that installing in dual boot is any more complicated than a clean install, especially given the state of modern Linux installers