I just put a starter on my 1993 gmc Sierra 1500 pickup truck.When I turn the key to on, all that happens is my dash gages and lights come on. It doesn't start nor is there a sound from the starter.

have you checked your ignition switch?

Are there 2 small wires that bolt onto the solenoid? or just the one. Never the less if you have a test light & a helper, when you turn the key the one or one of the two wires become live to activate the solenoid. Possible if two wires that there on the wrong terminals, and need to be switched. Same for the one wire, may be on the wrong terminal.