The automatic transmissions in many newer vehicles are sealed, the fluid intended for lifetime use in normal operation. Unlike motor oil Automatic Transmission Fluid (ATF) does not have to contend with byproducts of combustion, condensation or nasty gases. It simply lubricates and cools. A filter traps and renders microscopic gear particles harmless.
Change ATF only if it has been overheated, contaminated or the carmaker calls for it. There is a real risk a well intentioned ATF change will be bungled. Transmission fluid is strictly car make and model specific. It must adhere precisely to the automaker's formula. The manufacturer's branded ATF is best. Never put multi-vehicle ATF into your car. Franchised lube, repair and tire shops are notorious for it. Correct fill level is critical. Transmissions are unforgiving of fill errors.