Jackie Emery Andrus

2018 Chevy 2500 LT. Unfortunately going back to shop for second time. Thank God I have warranty. Going for emissions related problems. First time Coolant reservoir need replaced. Also noticed that none of my mirror lights work. I'm wondering if this an issue I could fix myself easily? Led backup lights also wont turn on even when I turn on bed light and put in reverse. I hope warranty doesn't give me trouble. I did not have a problem the first time with warranty. But with this "Service Emissions System:. Along with lights not working in mirrors. And to top it off I must have some sort of short where license plate bulbs are at. Plate lights wont stay on even with new bulbs.