Sorry to hear about your accident. First thing I would recommend is to see if whomever you guys rep, if you rep anyone, is offering any classes. If they are take those classes. That will get you right to what your company is doing. The next step is I would read what is commonly referred to as the Honeywell gray manual, aka Honeywell Building Controls or something like that. Trane also has some good manuals and be receptive to different ways of thinking. Do a search on this website and you'll find a link to the gray manual I am referring to. Read all you can about control theory and application. Hopefully you've had enough experience to decipher out some of the BS on theory vs. application, ie controlling a supply air temp setpoint to 55 deg f like it is a chilled water valve when it is simply on/off dx cooling. Some classes on basic networking would also be helpful as we are dealing with the IT/IS departments all the time.
I haven't learned "code" that is really running behind the scenes as most of my programming language is graphic based, but I did do some PPCL/line programming awhile back. I know I could do more if I knew the code, but for 99% of the applications what I have available for graphical programming works for what I need. The other day I decided I wanted to make my own "astronomical" clock and on the web I found the "code" to do it; however I did not know how to put that code into the code that was running behind the scenes of my graphical programming language. Anyway I ended up writing my own program with the graphical language and in testing it works. I might be a few days off after a few years, but it is going to be really close and besides for what I need if the parking lot lights come on a few minutes early or late it is not going to be a problem.
BTW - I like GMC's.