Can I get a loan to buy a used vehicle from a friend

I'm sure you can. I would suggest you contact an online lender or your own bank. You can also use one of the third party lenders that Cargurus uses by clicking on the Finance tab at the top of the screen to apply.

Yes, then you would be paying cash. On a personal note I would suggest you and your friend make up a contract. Print out 2 copies. You and your friend sign both copies, and you each keep a copy. That way they'll be no misunderstandings. Hope that helps! Jim