New or used, depreciation is instant on all cars. Cars are not an asset and will always loose value. I have owned used and new. In the end I found that the overall cost of a new vehicle is not significantly more than for a used car. In most provinces you are required to do annual or bi-annual vehicle inspections. Mechanics always find something that is wrong and often things that cost a lot to resolve (for compliance). Especially true for used cars. New cars have warranties, and more often than not services are free or partially free.
If your annual mileage requirements are not too high, I would consider a lease. I love it and probably will never buy a car again. Counting depreciation, maintenance and monthly instalment as well as possible tax benefits (depending on your job), and the fact that you always have a new car with the latest safety technology, it just makes more sense. The reality is that no matter what, your car ends of just being a rental anyway (counting the money and value) no matter whether you actually own it or not. If you see it in that way it makes life simpler.
Unless you are buying a car for another reason (maybe a vintage car or something else) does not make that much of difference cost wise, but it is much nicer having a new car all the time. If you decide to buy I would suggest buy new and flip ever 4-5 years. That way you pretty much only pay the monthly "rent" for a few years and then get a new one when you are tired of it. Best value for your money overall.
If you are on a restricted budget then I guess cost will dictate your choices and they get less, obviously.
Just my thoughts on this subject.
Good luck