Visiting Canada for the first time, need suggestions for what to do and see

I'll be making my first visit to Canada this summer to see my girlfriend who lives in Orangeville, Ontario. I was wondering if anyone had any suggestions for anything we should do and see while I'm out there? Obviously theres gonna be plenty to do in Toronto but I'm not sure what. The only thing we have planned is a visit to Niagara Falls at the moment.

Also does can anyone give me a decent rock bar/club, preffably that has live bands, in Toronto that we could go to one night?

I've never been on a plane before, and this will be my first time abroad without my parents, so I'm hoping it's gonna be a good 2 weeks

 

http://www.city.toronto.on.ca/