I put that at this bottom but will also post at the top so it does not get glossed over.

In the end you need a skill set that is interchangeable across many fields. Having a good foundation in electronics / electrical / pnuematics / hydraulics / mechanical systems will accomplish that.

If you work for a company that touts " Furnace inspection $ 20 " / " Same day service or you don't pay " / " 20 outlets- switches for $ 20 " , you can be assured that you will be pushed into selling marginally needed services.

If you do go down the path of electrician / HVAC , try to lean towards the commercial end of things. If you do residential repairs, you will be educating every customer you come across where as commercial customers generally understand what is going on.

You see the number of people on this list that cry that auto mechanics are evil and charge too much, same thing will go on in the residential side of things.

I probably would not work for a new house builder, everything is about speed and low cost.

Computer programming will do zero to help repairing a car, having electronics knowledge will. Also, electrical ( house wiring ) and electronic skills ( fixing a TV ) , are not the same thing but it is possible to know both.

Some other things to consider. Are you willing / able to do the work you chose on a daily basis when you are 65 ? I got out of the day to day auto repair business at 34 because I could see there was a hard physical road ahead. I moved into industrial / factory machine repair - design. Half of my time was spent in the office doing research / design / directing others and the other half on the floor doing repairs.

Now at 55 I've semi retired and do work for various businesses when they need high level electrical / electronic / mechanical help. This leads to the importance of having a good reputation.

I recently stopped at a machine shop to have something surface ground. The knew me by rep, didn't remember my name but after an actual minute of conversation wanted me to look at a machine that was not operating. This Russian horizontal mill built in 1974 , had the control electronics up graded in the mid 90's and has zero documentation for the upgrade. I'm being tasked to get it running, generating wiring diagrams and documentation. The control cabinet is the size of 4 refrigerators and it pretty full of PLC / relays / contractors / DC drives .

In an area where cost of living is low, it is going to pay in the area of $40 / hr. Their other machines desperately need attention so this is likely to lead to near full time work.

In the end you need a skill set that is interchangeable across many fields. Having a good foundation in electronics / electrical / pnuematics / hydraulics / mechanical systems will accomplish that.