I'll take the easy one first ... "LOL" = Laugh Out Loud ...
LOL

As for the 'numbering system, I believe C4 refers to the 4th "C" position on the piano, so if playing you would hit "C" 3 times (but not knowing what the time value is - 1/4 note, 1/2 note. whole note, etc.), then hit "C" again, then the "E" above that then the "D", etc. etc.
I think I might know how the melody would sound, but without my kb near I can't be certain ...
But you gave a good list to start with ...

t.