If you can afford the car, you can afford to take good care of it...
I work on gearing and lubrication applications for a living and here is my .02$
Don't mix lubricants...(some manufacturers use additives that may not mix well)
Change the oil and filter.
Be sure to install the lube recommended by the manufacturer's owner's manual.
(Take climate and season into consideration)
ATF doesn't last forever. Have it serviced by a qualified mechanic and you will have a long and happy relationship with your new baby.