Like you, I really enjoy bicycling, and more so when I see other people enjoying bicycling. Nothing detracts from cycling enjoyment faster than attempting to ride a bike the wrong size, or having a bike poorly set up for the rider.
I've been riding since my parents gave me a bike for my 6th birthday, but it wasn't until nearly 40 years later while working in bicycle retail that I really understood the importance of bike sizing and bike fitting. Yes they are different things. I've now ridden bikes (many types), sold bikes, sized up riders' for bikes, and established an independent bike fitting studio. Doing bike fits is my main "day job".
In 2015 I became the owner of Fit Kit Systems, which was the first business to bring science and education to bike fitting in the USA, starting back in the early 1980's.
I enjoy keeping abreast of developments in bike fitting through attending conferences and talking to other fitters, but my greater satisfaction comes from teaching fitting to others and sharing my insights and experience. If you can't make it to a face to face, hands-on workshop, an online course is a good place to start. Enjoy your ride, and help others enjoy theirs!