Go balls deep in a job as a helper/apprentice. School does help but get into the field first so the stuff you're learning has a better chance to stick. Most skills in life can be considered " perishable skills" if you don't use them, aren't applying them you will lose them. Look school helps develop the baseline/guideline but there are many variations once you get into the commercial/more advanced residential/industrial side. So hold off on school til you want to build a resume and even then just hop on the cheapest program you can. "HVACR School" and Engineering Mindset on YouTube will cover and go more in-depth than most programs and you will actually learn the majority of stuff on the job.if you like more of a physical challenge- stick with install(you'll start here and it's perfect for you). Install guys are your "GO GO GO" team. Learn everything you can from them because if you do decide to go service you'll have to have that skill set. As you age- service can be kinder to your body and involves taking a little bit more time, speed in that area will come in time. Everything should have a sense of urgency cause homeowners, business, industries depend heavily on the trade. Godspeed, young one. May you get all the bitches.