Many people do dual drives, but if you install linux second and it is a distro thay uses grub with probe foreign OS them you don’t really need two drives. make space on windows drive, in the linux installer create another boot partition, root and home. You set bios to boot Linux grub. Grub will launch and give you linux or choice to chainload to Windows. Windows is unaware it is getting kicked off by grub so the Windows and Lunux boot partitions leave each other alone. i can’t vouch for every distro letting you setup like this but this is how my OoenSUSE has been since 2017