What is the first step that a smart new-car buyer should take before talking to salespersons and putting a deposit on a car?

Researching online to find the best stuff for it's value

ex. try to find the best kind of car that you can buy with the least amount of money

researching by yourself is important because you will know alot and if the salesperson says all good things about a product, you might know some downsides and mentally be prepared lest you get a car you don't like