You can jury rig your controller. - But be very careful if you are afraid of electricity.
Just for test only!
1 - if you have 4 used 12-volt batteries, they don't have to be large capacity for testing. Connect them in series to add up to 48 volts dc and connect them to the DC input of the controller.
2 - Take an extension cord, #14 gauge or more and cut the receptacle end off (leave enough of the cord connect as you will be using it latter) and connect the wires to the ac input of the controller. - I'm assuming your input to your controller is 120vdc. Connect the plug end into the 120vac house outlet.
3 - Take the receptacle end of the cord you cut and connect those wires to the controller AC output and connect any ac load to into the receptacle end, I used a 200-watt bulb that I had laying around for my test load.
Except for testing the solar panel input, there are several tests you can do. I did all my testing that way with my MTTP 2424LV. then when I got my solar panels, I connected them to the controller to finish bench testing before I connected it to the Utility and house loads.
Please note, that I'm a retired Electronic Engineer with many years playing around with electricity. If you are not comfortable around electricity, don't do what I mentioned above.