First time car buyer

Hello I am a 33 year female living in GTA. I got my G2 in July 2025 and have just 2 years driving experience. I want to buy my first car that is low maintenence but suitable to drive in the crazy Canadian weather I don't know much about cars but I did my research and I figured either Toyoto corolla or Mazda 3 would be the best choice. I am leaning towards Mazda 3 because of some features. I would like blindspot monitorina, a front camera( know it might not be available in low end cars) and heated seats My budget is 15-20k. I have saved a bit and thinking of buying a used car with cash. Can you please let me know what are the essentials that I need to see for eg kms driven, year make and is Clutch.ca reliable or should I go to dealership. And any dealers you can suggest in GTA area

I am also open to other car suggestions as well. I would really like a compact SUV that can come under the same budget