when and how often should I change my oil?
According to either your oil life monitor, if so equipped, or per time and mileage as specified in your owners manual.
If your vehicle has an oil life monitor, change it when it gets to 20%. Otherwise, whenever your owners manual tells you that you should
Ah, the owner’s manual; the world’s most UNREAD Best Seller!
Also make sure you put in the right weight and spec of oil. The owner’s manual also has that info. Jiffy Lube will put in whatever is the cheapest thing in their tanks.
The car is 4 years old. What has been the regimen up to this point?
If the car is new to you then you have no idea how the prior owner treated it unless records are provided and that seldom ever happens.