yes partitioning is the correct term, and windows already has a tool for managing disks. you should find it as disk management or something similar. then as you install linux, it should give you the option to install alongside windows. but for this to work you need the usb drive to be flashed correctly as gpt or mbr depending on which one your windows has (type “list disk” in cmd and see if theres * under gpt), and rufus lets you choose this for your distro, so pick the same one. i have heard windows updates may wipe the bootloader, but you should be able to just install it back if that happens. i never update as i only use windows for my school stuff anyway. linux will not wipe windows unless you choose to do so in the installer.
i’ve had glasses for a little over a year now and this is what i too have been doing since beginning. i thought it would be bad for the lenses and remove the coating but kept on doing it anyway and they are totally fine. i keep a soft cloth in my pocket for little smudges though.