Clutch has little to no resistance; cannot change gears at all.

Hello, Yes, the clutch reservoir is likely empty, but that signals a leak, not a need to refill. You will need to track the leak down, and likely replace the clutch slave cylinder and/or clutch master cylinder. Note, these systems may use brake fluid, and may be located near the brakes, but this is a completely separate master cylinder than the brakes. If the leak is slow enough, you may be able to refill and bleed air from the system to drive it to a repair facility. If you are doing the work yourself, and have questions, post back here and I'll help you out. Otherwise, check out the certified shops in your area here: http://repairpal.com/ford-within-10-miles-of-pocatello-idaho-83201