If you can't see anyone on that channel, it might be due to two reasons (that I can think of right now):
1. there's actually no one in that channel, because it has been shut down OR because you've connected to a different network (i.e., this channel used to be on irc.network1.net and now it's on irc.different-network.net, and any of its variants).
2. There's a netsplit (for further information on netsplits, look
here.)
As mentioned above, the 'search' command is specific to a channel, so you have to ask the people in charge of the channel (in case ANYONE's in charge of a room called #xxxpasswords :lol:)
If the help you're looking for is not detailed above, try this:
/server insert.network-name.here in any mIRC window (i.e., your
status window) will automatically connect you to a server.
/join #channel will join a chat room.
Other commands, such as @search, @find, @gimmeyourpasswords and such, belong to script-controlled bots, and you'll have to ask someone else.
Hope it helps