So, to start this off, I don't have a lot of money.
So I have a factory second Epiphone guitar.

And, to make it oh so much better, I have Medium Diaddario strings for it.

Anywho, what's the cause of the bad sound, the guitar, or strings?
No, I'm not the best guitar player, but I'm not bad enough that my playing is the reason for the bad sound.
most epiphones don't sound that good, but before giving up, i suggest you try a set of martin silk and steels - they're so good they improved the sound of my rogue beater dramatically.