Purchasing a used car in Houston

I’m looking for a used car and everyone I’ve come across so far (3 people) do the same thing. They have the car title in the previous owner’s name that sold it to them. That’s weird to me as I thought the title name ought to be the person selling to me.

Also, they all had 1 key instead of 2 keys. For me, a car being sold with 1 key could be a stolen car although the VIN checked out for all the cars.

Is this a regular thing here, or should I be worried?

P. S: they were all private sellers