How often is toyota avalon should get oil change?

My question is the title, I thinking of purchase a used avalon, any tips to know how good condition the car in? I am first time buyer... thank you, really appreciate it guys.How often is toyota avalon should get oil change?Most people go with the 3 month 3,000 mile concept although it's not absolutely necessary as the manufacturer suggests about twice that between oil changes. Have a reputable shop go over the car to give an idea of it's true condition. This won't be a guarantee there won't be problems but it's much better than buying %26quot;blind%26quot;.How often is toyota avalon should get oil change?Does the seller have a maintenance history of the vehicle or not ?? Either way, it would be worth it to have a mechanic do some diagnostics to see if any repairs are needed now or soon..........call it cheap insurance