when I enter mIRC I go to channel but there's only me there and it should lots of ppl there if you know what I mean.
what's the problem plz help
I mean what's the point of having mIRC when you cant chat with any1 :P

You're probably joining an empty channel. If it's a channel you've used previously you may have been on a different network. #mIRC on UnderNet is not the same channel as #mIRC on DALnet, for example.

If you can't remember what network the channel was on you can try searching at SearchIRC or netsplit.de.

You can also use the /list command to list the channels on the currently-connected network.

You may also be on the "wrong" side of a netsplit, where some people on a network are on one group of servers and some are on another, but those servers aren't communicating for whatever reason, so the people on one side cannot see or interact with people on the other side (note that there can be more than 2 sides in a netsplit). Just try connecting to a different server on the network.