Should I mail my transcript to university of Waterloo before I get?
You can, but you dont need to. I guess that you have applied through QUEST and you might have already uploaded some version (maybe unofficial) of your transcript. Once accepted, you will be asked by the University to send an Official Transcript (with the seal of the University). As for your second question, you will have to include the grades for all the terms (or whatever the university asks for). Hope this helps !!