Applying for a car loan will put a hard inquiry on your credit score.
However the hard inquiry will only affect your credit score for a year or less before it drops off your credit report.
The hard inquiry may lower your score by a few points but it doesn't lower the credit score too much.
However if you do get the car loan and then pay the car loan payments on time then the credit score will build back up and then the credit score will be higher.
You usually need around a 600 or above credit score to get approved for a car loan unless you can get a cosigner to help you sign the car loan note.
You also need some money down usually depending on the car financing company.
If you're buying a new car or new truck etc then you usually need $3,000.00 to $5,000.00 down depending on the price of the vehicle.