Ubuntu Dual Boot Preparing

Preparing for a new AMD pc and wanting to play around with dual booting still. I need Windows for 1 thing and slowly checking if everything else I use works in linux. Next is to dual boot from an external SSD and trying running that 1 thing in whatever Windows emulation I can find for Ubuntu.

Found this nice guide that sounds like it doesnt mess with the original Windows 10 I have installed.

https://askubuntu.com/questions/726972/dual-boot-windows-10-and-linux-ubuntu-on-separate-hard-drives?newreg=5004204f6d664e6ebe17e85d5ca08f17