Below is an example of what could and will go on a typical channel (although this screen shot is from a previous version of Homer, it still supplies the information of what goes on in a channel).
From this window, you can see:
1: I am on the channel #talk
2: The topic is "THIS SPACE INTENTIONALLY LEFT BLANK"
3: I do NOT have Operator Status (my light is not lit)
4: The mode for the channel is +tn (t and n switches are up)
5: They don't know me on here.. noone says 'Hi' to me.
Basically, some channels are full of discussion, some are not. People could be talking in private messages and some could be sleeping. You'll get the hang of it.