First check if your volume is up.......
If you still have no sound coming out......Open the ends up on your amp chord and see if the solder is still good.....Most of the lower end amp chords break really easily.....You can usually solder them back on. Sound quality is never the same again though.......
if that is not the problem. flip the guitar over and open up the cover lower left corner, Check to see if all the ends are soldered there.......That is a lower end Epiphone guitar, i've never had problems with soldering on my epiphones, i've got 5 Epiphone SG 400's.... I've always had problems with my Strats and corts though.......
I am bias though, I am a Gibson/Epiphone man lol
Did you get one of them guitar packages with the amp and guitar in one box? If you can't find the problem with the soldering i'd take it back.........
You can get a good SG special for 150 bucks, and go grab yourself a good 30 watt fender twin reverb for another 250.....You'll be set...........
I still use my Fender Reverb 30 watt as my main house jamming amp. Been going strong for 10 plus years.............