My 1994,2.3l,4 cyl Ranger will not start. When I go to start it, it makes a single clank type sound and that's all.

 

If it is a manual, put it in 4th, and rock the truck. That will move the flywheel a smidge. Then maybe the starter gear teeth will engage.
Sounds like your starter or ring gear teeth are worn, or the battery is low on charge, or the starter relay semi-functional. All the above can cause the starter to clank, and fail to turn the crankshaft. The solenoid on the starter, if separate, could also be failing. The older starters had a 'ramped or tapered bump' on the starter which functioned the same as an external solenoid.
tom