Yo Gibson guy. That rocks. It's weak, but it's a start. Now you need a cheap mixer. Check the impedence on the output of the power amp. Often, power amps are made to drive a pair of 4 ohm monitors. Some power amps can be "bridged" to 8 ohms, combining the two channels into one 8 ohm output. If you don't have a manual for the power amp, try to find one on line. It will help some. If the amp can't be bridged, and only does two 4 ohm channels out, you can use one side to drive the cab anyway. It may or may not sound good. If the amp has any kind of 8 ohm output, with or without bridging, turn the damn volume down and be careful. That's a 60 watt cab, not a 125 watt cab, and in some cases, a cranked up power amp inadvertently turned on with a live mic can fry a speaker cab spectacularly.
Now you need a preamp, and for you, a mixer is the cheap way to get a preamp, in fact, several of them. Best cheap? I like the Yamaha. Yes, I know the Behringer has a low price, and excellent features. I don't like the way
they sound. Yamaha starts at about $100 for wicked basic. The $200 version is much more versatile. The cheap one will drive that power amp, alright, so you at least get vocals to start practicing. Good luck.
We're all in this together. Keep your stick on the ice.-Richie