I have been to every Canadian GP held since 1989 and one thing I would stress, don't carry a lot of stuff; it's a PITA on the Metro and difficult to stash once at your very crowded seat. A camp chair is a good idea as it gives a clear line of delineation for where your seat is. Don't be that guy that stands up when no one in front of you is, everyone behind you hates that guy.Buy an unlimited Metro weekend pass, you won't need your car; park it and leave it. Montreal is a very walkable and safe city and there are cabs everywhere. The Metro train you want is denoted by looking at the terminus of each line.
So if you're on the "Green Line" entering at McGill headed to the race, you'd want the "Honore-Beaugrand" destination and exit 3 stops later at "BERRI-UAQM" to get on the yellow line headed for Longueil (or just follow the people wearing race gear).
People in Montreal will great you thusly: "Bonjour, Hello" your cue for desired language depends on your response so answer in English. In nearly 30 years I have met less than 5 people who don't (won't?) speak English.
There is wi-fi in the grandstand you're in I believe (there was 3 years ago when I sat there) so if you have a smart phone, download the F1 App so you can follow the timing and scoring, especially for qualifying. You will be able to hear the announcements sporadically and they are given in English and French. There is some muddy bits between the Casino and your grandstand. Also, there is ONE bridge for all the people sitting in the Senna section of the track, i.e.-be prepared to wait. After the race you can walk the track which is pretty cool.
Here's where I'll be:
Two years ago with the Wee Scotsman:
Nephew's first GP and he gets a pic with Nico, we had a rockstar weekend meeting Lauda, Charlie Whiting, JV, Coutlhard, and Eddie Jordan.