Just in case you didn't know, Montreal is a French city! All the government and city signage will be in french and it's the go-to language in restaurants and shops. But! don't be afraid! Nearly everyone also speaks excellent English. (It is nicer to at least try some French, a Bonjour-Hi is appreciated.)
Americans! Please don't try to rent a car unless you are planning on leaving the island! There is very little parking, it's a hassle and the public transit is excellent. On the travel page, we have a link to the STM website to learn what fares you might want to purchase. There is a Metro and quite a few bus lines. The city is very walkable, but to get from neighborhood to neighborhood you might want to take transit. The STM fare covers the metro trains and the buses. If all else fails, call a cab (or an uber if you don't tell JP).
If you are an American traveling for the party you will need to go through a few extra steps to get into Canada under the Covid-19 restrictions. As of right now (April 20th) you will need to have a record of your full vaccination and records set up on ArriveCan and VeriFly. https://travel.gc.ca/travel-covid/travel-restrictions/covid-vaccinated-travellers-entering-canada#entry-vaccinated https://www.canada.ca/en/public-health/services/diseases/coronavirus-disease-covid-19/arrivecan.html https://www.myverifly.com/#/ https://ca.usembassy.gov/covid-19-information-canada-3/
Right now in QC, you have to show a vaccine passport to enter a restaurant or "non-essential" service. If you don't live in QC or were vaccinated somewhere else, you can just bring a photo ID and a copy of your vaccination record (it will need both dates to prove full vaccination).