If you want the 64 bit version, you can't install 32 bit OS and "upgrade" to 64 bit OS. It will take a new "clean" (reformat hard drive) installation to install the 64 bit (and you don't install it from within an OS).
Before you go any further, verify that the current hardware you have is fully Windows 10 compatible. Many older Win XP machines hardware is not compatible, or only partially. Even some Win XP machines were not upgradeable, to Win 7 or 10 due to hardware. One device that must have Win 10 drivers is the sound. The XP drivers and even Win 7 drivers for the sound are not compatible with Win 10.
Another compatibility issue is your recording interface hardware.
Its possible everything you have is compatible with Win 10, but do your homework and verify first. AND, make a full hard drive backup (disc image) of the XP drive to some other drive, in case you want to go back.