Do you enjoy working with your hands in hot environments? That is the job of an HVAC technician. While it is a steady job, It is a hard job. Find an HVAC technician in your area and ask them if you can take them for coffee/ cold soda. Then pick their brain on what the job entails and what a day in their life looks like. Then ask yourself if it sounds like a job you could do every day, rain or shine.
If you decide it is, great- your technical/ community college in town will have a degree program for you. If it doesn't sound like fun- you have saved yourself time and money.
a job with a skill set / certification in HVAC is a good job in terms of stable employment opportunities and job security. Every build made in America has code requirements for HVAC systems so in this sense you know you have steady demand in every part of the country. To optimize your earning and upward mobility potential you should focus on cities that are growing and building a lot - both residential and commercial. In addition, you should try and specialize and find ways to expand your core HVAC knowledge base in areas like energy efficiency and LEED certification.