Toronto has an extensive public transit system of subways, buses, and streetcars. The airport is fairly far from downtown, I would suggest a cab or limo for that trip. Public transit with your luggage won't be fun. Your cell phone should work but you need to check your carrier and plan. Voice roaming will be expensive, data roaming will be astronomical. You may be able to switch to a plan that includes Canada for a month right before you leave. ATM card will work if it has a logo that matches the machine (Plus, Cirrus, etc). Call your bank before you go though, to let them know you will be out of the country.