I'm trying to do a game, which uses Match 3 mechanics too. Yesterday I found:
weconstruct.blogspot.com/2011/12/match-3-in-construct-2-part-one.html
It takes only five events to generate grid with random objects. Shame there isn't part two (and most likely won't appear), because I'm a beginner too.
Now I struggle with proper swaping of them.
EDIT: Thanks, vee41, for these links!