I don't want to spoil you, but I've struggled too so: here's an help !
First open the terminal and type : ls /Alex/Applications
And then you try to open the M.Net_Chat.play using the techniques that Laguna teached you (./Alex/Applications/[App_Chat.play])
Then she will explain to you how to go further.
If yo don't figure out the password, keep exploring using the same techniques, but if you still don't figure it out : ALEX is the first password and then you'll see \(^-^)/