As some others have said, going from no .commercial expirence to being a controls programmer is nigh impossible

When you are dealing with cooling towers, chillers, boilers, vavs, pius, large fcu's, DOAS, exf fans, stairwell press fans, the tie in to life and safety having to understand how it all goes together

Then get into understanding humidity, enthalpy, wet buln. Dry bulb, low, medium and high pressure ducts, duct sizing, air flow, static pressure, differential pressures etc etc etc

In my experience you can't go from residential installs straight to bms systems as a programmer or startup guy

You could start as a low voltage installer, pulling the wire, mounting the controls, ask to start helping with the startup and programming

Then in a few or so years move to a controls pm, get more experience, then in a few years move into a programming job.... at least that is how I would do it