Training to be a HVAC tech

You know how all the people consistently says that family is supposed to stick together? That phrase has actually started to haunt me other the last few afternoons now that my Heating, Ventilation, & A/C heating & cooling unit broke down. I have been using the same unit for the last several years, & one afternoon when I came home from toil I noticed that there was a small stream of thick smoke coming out of the heating & cooling unit & it wasn’t even making a sound. Later that afternoon I was venting about the Heating, Ventilation, & A/C unit breakdown in my family group chat, & my sister suggested that she could come over & try to fix it up for me. I had totally forgotten that my younger sister had been trying to become a certified Heating, Ventilation, & A/C repair man for the last few weeks, & now she knew I needed some help with my unit. However my sister is one of those people who thinks they are skilled at several things in life, but actually succeed with undoubtedly few of them. One of those things my sister lacks skill with is most undoubtedly being an Heating, Ventilation, & A/C repairman. She is my sister however, so I look care about a jerk if I don’t end up having him come over to toil on the unit. Now I am stuck between calling my proper Heating, Ventilation, & A/C corporation to send out a repair tech, testing my luck with having my sister try to toil her magic on the unit. I am starting to assume that I will just throw the entire unit out & just buy a current one to avoid all of this annoying family drama!