Enjoy your car! Just do basic maintenance, especially for safety-related items, brakes, tires, lights etc.
And stay safe! Above all else, don't drink and drive! Just say No. Your friends will respect you for it.
Know that your age and gender could put you at high risk of an accident. Don't be a statistic.
https://www.cdc.gov/motorvehiclesafety/teen_drivers/teendrivers_factsheet.html
EDIT: Sorry if this sounds like preaching. But I had 3 boys, and they all had accidents soon after getting their first cars. Fortunately nothing serious.