To expand on this (very correct reply), simply download the win 10 install media from microsoft, run the install, during setup it will ask for your licence key and there will be a little icon saying something like “I don’t have my key handy I’ll do it later” the install will then finish fine and the only restriction is you can’t customise wallpaper.
Other things to note, do NOT connect it to the internet when you’re installing, let it moan and then you can create a local account. Otherwise it makes you setup a microsoft account.
Do use 10, don’t use 11.
Dual boot works but windows has to be installed first and it will mess with your linux boot - backup your machine before install. I’d run up a windows Virtual Machine first before doing a dual boot install if it were me