If you’re buying a car and are on-site with the vehicle, you’ll first need to determine how many owners it’s had previously. You can look in the vehicles service book as it should mention the various owners it’s had.
It’ll give you a chance to look through the service record to see if there has been any glaring issues with the vehicle that could cause issues in the short term. Also taking a look at the MOT history is a good idea, as once again you’ll be able to see any issues that were found during the MOT and if it passed or failed.