Just wear what you want. Not a problem at all. Actually, suite won't fit for the thing. You will see lots of refugees with kids, so... You know what I mean.
The thing is long and boring. The lady will tell you lots of stories about how canada is "heaven" for people who had terrible lives that kind of shit. I think all she want to do it to make sure it's longer than an hour so you will pay more parking fees.
More than a hundred people will be there, so, you don't have to sing, no one can here anyway.
Happy oath.