ok so ive been licensed for about 3 months now and i keep hearing people throw out all these Q codes and abbreviations and honestly i only know like QSL and QTH and thats about it. was on 40m last night and someone was asking if the other station could QSY and i kind of figured it out from context but i dont want to just guess every time. is there like a master list somewhere or do people just memorize the common ones over time? also what does 73 actually stand for, someone told me it means best regards but where does that even come from, feels like it could be a whole rabbit hole

yeah you'll pick most of them up just from being on the air honestly. the ones you really need to know starting out are QSY (change frequency), QRM (interference from other stations), QRN (static/natural noise), QRP (low power, like 5 watts or less), QSB (signal fading), and QRZ (who is calling me). QSL you know already which is basically acknowledge or confirm. people also say QRX which means standby or wait a minute.

as for 73 thats a great question actually. it goes way back to landline telegraph days, there was a list of numeric codes and 73 was assigned to mean best regards or something similar. hams just kept using it when radio came along. you'll also hear 88 which means love and kisses, usually said to a spouse or close friend. some old timers use 55 for good luck. most of the numeric ones have fallen out of regular use though.

the ARRL website has a pretty decent reference page for this, also the back of most license manuals has a Q code table. but honestly dont stress about memorizing all of them at once, there's like hundreds of official Q codes but most of them you will literally never hear on amateur radio. QRM, QRN, QSB, QSY, QTH, QSL, QRZ are probably 90% of what you'll actually encounter day to day. oh and QRP gets thrown around a lot too especially if you get into that side of the hobby. i was in the same boat as you when i started, just listened a lot and it clicked after a few weeks