Best way to buy a used car ?

Need to buy a car within these next 2 weeks. Been using carfax app and it’s been helpful. What’s the best way to ensure I don’t get scammed in terms of knowing the car has a clean title or not ? Is the only way to use the vin number in one of those sites where it lets you look it up, and how legit are those websites ? I’m not really a car person I would appreciate all the help I can get. Also what would be the best way to buy a used car fast overall? Thanks.