I do not like throwing new people into installation. I feel if you take someone new who doesn't know anything (and trust me right now you don't know anything) they learn how to do things in an order and repetition but they don't learn anything about air conditioning.
You teach some one how to attach this color wire here, braze that like this, connect the duct work like this, and so on.
Then you have someone with more experience come in and fix any problems, vacuum the system, and start it up.
I prefer to stick new guys with the PM department, with a seasoned tech who needs a helping hand, move slow, teach what the parts are, how they work, how to diagnose problem, then after 6 months to a year you send them to do installs. Now they have an understanding of how the system works and how bad installs cause problems. They can use that info to do a better job and now they learn more about installing and have thee foresight to see an installation error.
Then you make them a service technician. Now they know how it should have been installed, how it should have been taken care of, and why it isn't working. They are much faster at diagnostics and have a better understanding of what is required to change out parts well.
I hate when companies train guys how to be mechanical monkeys instead of intelligent mechanics.
If you're too "open" minded, your brains will fall out.
Artificial intelligence is no match for natural stupidity.