Everything depends on your pocket.
1. Owning a car is all about how much you can afford, the common Japanese and Korean cars like toyota, honda, hyundai, kia, mazda e.t.c are a bit costly than the average american car and are very good on gas.
2. You can get cars on kijiji, auction, dealership, private seller e.t.c
3. Cost are determined by mileage, condition, year, model(trim level), brand, neatness e.t.c just like in Nigeria or anywhere in the world.
4. Insurance could be third party or premium. The amount you pay sometimes depends on your address(post code), province e.t.c Premium are usually costly. Insurance are usually paid monthly too.
5. With dealership, be prepared to pay taxes, dealer fees, cost of borrowing e.t.c
If you want a finance through dealership, they would need your credit history, down payment, paystubs e.t.c and of course payment bi-weekly or semi-monthly for a couple of years.
For $3-4k, the likely Japanese car would have high mileage or low mileage 1990's year(rare).
I also noticed cars are cheaper in eastern Canada.
But most important is to
pass your driving test 
