Ask if you can take it to a mechanic and have it checked out.

I once bought a beautiful van but didn't have a mechanic check it until I had already paid for it. The mechanic said the front end would fall off at any given time and it wasn't safe to drive. The seller argued and said the mechanic was lying and refused to take the van back. I parked it and about a month later, I sold it cheap to get it out of my driveway. A guy with a tow truck came to pick it up and once he had it moved, he knocked on my door to tell me the front end had fallen off and I was lucky I wasn't driving it down a street or highway.
Get it checked out BEFORE you buy it.

Research the car make, model, and year online for complaints. Wish I'd done that before i got the vehicle.

I alwasy ask what engine it has. I perfer hondas because personally they are the easiest cars to maintain.

Is the car for sale. It’s important to ask that

Has it passed emissions?

How many miles are on it.

don’t forget to ask ur intuition if its the right choice for you

If the registration is recent or when is it going to expire sometimes it’s cheap for a reason

And check the engine if you’re good at checking engines

leaks underneath
tires
transmission fluid color
carfax report to verify mileage etc