help lol

[*LS1* Queen]

ok so my car started misfiring like a mofo a couple weeks ago. At first i thought it might been bad gas so i let it run low and put some injector cleaner in..still running like shit. Then i thought it could possibly be a coil pack cause my car is notorious for going through those and never throws a code.. well it finally threw a code and i got a P0300 which is a random/multiple misfire code which is nice and vague lol. I started testing the coil packs to see if they had spark but i didnt get through all of them yet cause i electrocuted myself and got mad haha..and as far as ive read this code can be thrown for numerous things O2s, bad plugs/wires, coil packs, injectors etc and i have no idea where else to start. The car was running awesome before all this happened so im a little clueless right now and i really dont have the money to just start throwing parts at it.