ok so I just got my technician license like three weeks ago and ive been trying to get into the local 2m repeater listed in the repeater directory. The thing is I can hear people talking on it just fine but when I key up nobody seems to hear me or acknowledge me at all. I did the whole "this is [callsign] listening" thing a couple times and nothing. My radio is a baofeng UV-5R and I programmed the frequency in but I honestly am not 100% sure I set the CTCSS tone right. The directory listing shows a PL of 100.0 and I think I set it but maybe I got the wrong menu or something. Also a side question — is there like a rule about how long you should wait between transmissions before jumping in? I dont want to be that guy who steps on someone mid conversation. Any help appreciated, been trying to figure this out for days.

The CTCSS thing is almost certainly your issue. On the UV-5R it's kind of buried in the menu — you need to make sure you're setting the T-CTCS (that's the transmit tone) not the R-CTCS which is just for your radio to squelch on receive. A lot of new folks set the receive side and wonder why nobody hears them. Go into the menu when you have that channel selected, look for option 13 which should be T-CTCS and set it to 100.0 Hz. The directory listing showing "PL 100.0" means the repeater requires that subaudible tone on your transmitted signal to open the repeater's squelch, your voice going out without it just gets ignored by the machine.

As for waiting between transmissions, yeah there's kind of an unwritten rule that you pause a couple seconds after a transmission ends before you key up. Gives the repeater time to drop the courtesy tone and lets other stations jump in if they need to. If there's an active QSO happening, best to just listen and wait for a natural break, usually happens when they say "go ahead" or toss it back to anyone listening. You'll get the hang of it pretty quickly once you're actually making contacts on there.

yeah what he said about the T-CTCS menu, that got me too when I first started. also just a thought — some repeaters around here have a timeout timer so if you key up and nothing happens for a few seconds they just drop you. might not be that but worth knowing. once you get the tone sorted out you'll probably be fine, the people on our local machine are pretty welcoming to new hams checking in.