so ive been licensed for about 3 months now and i keep seeing people use these codes on the air and in posts here like QSL and QRZ and QTH and honestly theres like a hundred of them and i dont know which ones actually matter vs which ones nobody uses anymore. my elmer just said "youll pick it up" but thats not super helpful when im sitting there in a pileup not knowing what anyones saying

also i see people use abbreviations that arent even Q codes, like 73 and 55 and stuff like that, are those in the same category or totally different thing. and sometimes i see people write like GM or GE and im guessing thats good morning and good evening but is that standard or just something some people do

basically just trying to get a sense of what i actually need to know vs what i can ignore for now. mostly doing HF SSB if that matters

okay so the ones you absolutely will hear constantly on HF are QSL (i confirm / did you confirm), QRZ (who is calling me), QTH (location), QRM (interference from other stations), QRN (static/natural noise), QSY (change frequency), and QRP (low power). those probably cover like 90% of what you'll actually encounter in normal operation. the rest of them exist and some are used in specific contexts like maritime or military history but on your average ham band you wont hear them much.

the 73 thing is completely separate, thats just old telegraph shorthand that got carried over, means best regards basically. 55 is less common, thats more of a CB thing honestly but some hams use it. GM GE GA (good afternoon) are totally standard, everybody uses those, nothing weird about it. on CW and digital modes youll see even more abbreviations like UR for your, ES for and, NR for number, stuff like that. but for SSB phone just focus on the Q codes i listed and youll be fine for a while

yeah what the other guy said but also dont stress too much about memorizing them all at once. i been licensed 6 years and there are still some obscure ones i have to look up. QSB is one thats worth knowing, means your signal is fading, youll hear that a lot on 40m when conditions are sketchy. and QRO is the opposite of QRP so high power. honestly just keep a little cheat sheet next to your radio for the first few months, no shame in that at all thats what i did