Basically doing my own AC device maintenance

Every year I am getting better at cleaning our AC device. There was a time when I used to just call up an HVAC company and have an HVAC technician handle the tune up. A cooling device tune up is not too extravagant and easily necessary. I don’t mind the time, effort and money spent on it! However, I would absolutely like to learn a new skill altogether, so slowly I have been doing a little of my own cooling device maintenance. I started out just swapping out our air filter once a month. I felt so empowered by that. Then I managed to learn to take the AC device apart to vacuum and disinfect the inside of it. After that I figured out that the cooling coil gets mold all over it very often. I now frequently wash that area. I then found that the reason our AC leaks on occasion is because of a clog in the condensate drain, normally algae. I have cleaned that up from time to time. Now I am moving into liquids. I have added refrigerant to the cooling component and lubrication to the fan motor belt. I feel the next step is being able to deduce worn or rusted HVAC parts. Then I will need to find a substitution part and make the AC device repair! Once I can actually handle all of that, I will no longer need to pay for cooling device service, I will be able to do every single part of it. That is a long time coming though. It is one thing to wash a dirty HVAC system, another absolutely to repair a cooling device. I don’t know for certain if I have the necessary skill set.
Cooling tech