If you put the clutch pedal to the floor, put the shifter in 1st and then, without moving your foot, the car starts moving forward you either have.....
a. Air in the system....the bubbles are stopping the clutch plate disengaging properly.
b. A faulty clutch master or slave cylinder....the fluid is leaking past the seals and the clutch plate is moving just like it would as you remove your foot from the pedal.
c. A leak somewhere....the fluid is leaking and the clutch is moving.
Have a look for obvious stains of leaking fluid. This is the most likely fault as you said the fluid was low. If the master or slave cylinders seals are leaking the fluid sometimes does not leak out just back into the reservoir. The master or slave cylinders can also leak fluid.
I have not had a look at my 94 slave cylinders but there is usually a bleed nipple on it. Fill the reservoir then get someone to press the clutch while you open the nipple. Close the nipple before they get to the end of the stroke. Keep the reservoir topped up and do this a couple of times to make sure there is no air in the lines.
Hope this helps.