I moveed to Toronto from NYC over 18 years ago.
1. Brampton is a suburb of the GTA near the Toronto international airport. There is a huge South Asian population there. But there are also large numbers in Mississauga, North York, Scarborough.... Rent can vary depending on where. If you are (near) downtown Toronto a 2BR can range from $1400/mo and up depending on how nice the building is and if it is near TTC. If you want a nice place downtown, you are looking at ~$2500+
2. Buying a car here is expensive so if you have a fairly new car, it is recommended. You will need to make adjustments to it to comply with Ontario laws (have km first for your speedometer, etc). The parking situation depends on where in the GTA you live. But one thing I can say is that parking costs in Toronto are much less than what I dealt with in NYC. Auto insurance varies also.
3. Nothing major. If you are from a major northern US city (like I was), it is a fairly smooth transition. Not much culture shock or anything. Things in general tend to cost more and taxes are higher (many goods have a 13% "sales" tax). So you will have less in your pocket. But there are more social services available (single payer health care, good maternity/paternity leave, etc). If you are a US citizen or green card holder, you will still have to file (and perhaps pay) US taxes even if you are completely settled in Canada. But that is true for any US citizen or green card holder living anywhere outside the US.