Purchasing a truck

You can do what ever that you and the seller agree to.

@F_O_R This is one of the most non-helpful "answers" I've ever come across (and I've seen similar responses of yours to other questions). Saying nothing would have been just as useful.

Yes but depending on whom your buying from it may have a few more steps.

If the seller will give you the car and title for payment on the spot you can drive it away. Is this more clear? You do know any transaction requires that both parties agree to the terms of the deal?

Well the op seems to be asking specifically how to purchase a vehicle THROUGH this site/app. Your answer more accurately describes car purchasing in general but nothing specific to the process as it pertains to this site/app. There is a "start purchase" button but its pretty difficult to find an illustration or explanation anywhere on this site that details this process. Does that button just allow me to initiate a bank/credit card transaction? What are the processing fees? How soon after clicking "pay" will the seller receive the funds? etc.

Qurali-he asked how long not what process? If you yourself is asking the you can follow this link: https://cargurus.helpscoutdocs.com/category/6-shopping-for-a-car