I see from your original post that you already know about using the correct repeater offset and PL tone.
My first experience with them (on 2M) was in the UK in the late 70's when the radio landscape was very different. 2M FM was very populated - both the simplex frequencies and repeaters. My local repeater, GB3MH, was continually busy for a few hours during morning and evening rush hours. In the hours in between, when it was less busy, there was almost always someone who would talk to you. I was away from 2M FM for something like 25 years, but I find it to be much less populated now. I didn't spend much time on the repeaters this time around, as I am now an HF guy, but my experience was that it was harder to find someone to talk to, if you didn't already know them. I would often call on repeaters (in my populated urban area) and receive no reply, so I'm going to have to disagree with Is99 on that one.
Some repeaters will drop carrier as soon as you do, while others will let their carrier hang for a short while after you release the PTT (if you have successfully accessed them). However, just because you can access the repeater doesn't mean you are putting a strong signal into it, so you should try to get signal reports. You can even send some machines a DTMF command, to which they will automatically reply with a single number indicating your signal strength into the repeater. You'll have to do a bit of research to figure out what each different machine can do. In the "old days", repeaters would often beep after a successful access attempt, but I don't think that behavior is very common anymore.
Anyway, for someone who rarely uses repeaters these days, I have rambled on for far too long. I know someone will correct me if I am talking out of my behind. Enjoy that Baofeng. They're so cheap, they might as well almost be giving them away with boxes of cornflakes!
OK, back to the front panel layout for my new regen receiver, which is going to use a lovely old National HRO dial and gear drive. It takes me ages to build this stuff, but it keeps me off the streets
Ooops, nearly signed this post with my callsign