pre-pick where I want to store files - instead of guessing half-way through

pre-pick where I want to store files - instead of guessing half-way through - & I looked under almost every pull-down menu & every pic (icon) I could find - a lot of rabbit holes but no joy. I would have liked to class the drives in 2 ways - 1 - most important for identical equip & 2 - for all that I need for when I plan to upgrade parts of my unit.