The local currency is the Canadian dollar, including the ‘Loonie’ ($1 coin) and ‘Toonie’ ($2 coin). While American currency can be used widely, many shops will impose a rather unfavourable exchange rate relative to what visitors can obtain from banks.
Toronto Tourism’s Visitor Map provides a good introduction to local places of interest.
Please see this listing of food and drink options near the conference hotel.
Nuit Blanche: Toronto’s “free all-night contemporary art event” will be held on October 5-6. Many exhibitions will be located within walking distance of the conference hotel.