ok so ive been listening on 40m a lot lately and people are throwing around all these like QSL QRM QTH and a bunch of others and i can only figure out some of them from context. is there like a standard list somewhere or do people kind of use them however they want? also i keep hearing people say 73 at the end of every conversation and someone told me thats like goodbye but i dont really get where that comes from. just trying to figure out what people are actually saying to each other lol

yeah the Q codes go back to like telegraph days, they were made so operators could send short codes instead of whole sentences especially when conditions were bad or you were working CW. QTH is your location, QRM is interference from other stations, QRN is static/natural noise, QSB is fading signal, QSY means change frequency, QRZ is like who is calling me. theres a ton of them. ARRL website has a full list and its worth printing it out and keeping it by the radio when youre starting out honestly.

73 is just the traditional sign off meaning best regards, again goes back to telegraph shorthand. 88 means love and kisses which you mostly only hear people say to their wife or significant other over the air. dont say 88 to random people haha

i was in the same boat like six months ago. the Q codes made sense pretty quick once i just looked them up but what really tripped me up was all the non-Q stuff like the 73 thing you mentioned, and also people saying OM which means old man but its not rude its just like how they say dude basically, and YL for young lady, XYL for wife. and then contest stuff is a whole other thing with 5NN and all that. just takes some listening time