Hello.
I think the first thing to do is to understand terms at first like in human body what’s the name of the different organs and what’s is the purpose of each one.
For that I think Rob Papen’s Book is nice, How to make noise series from Simon Cann is nice, (but there’s plenty) An interesting learn by practice with Syntorial is also a very good starting point. (I do recommend for that one to avoid headphones and learn on monitors because when it’s come to reverb and pan you will probably failed by small amount of errors with headphone it’s really hard in small adjustment to hear the differences)
When you understand the building blocs and different synthesis types. I would recommend to start by family and understand what’s make a Pad different from a Bass etc… and write somewhere a startup configuration for each one that way you can always start by these characteristics each time you want to design a particular patch.
Then I would start to listening presets on various VST, Gear… and Reverse Engineering those patch you really like.
Then I would try to recreate some very distinctive sounds you remember from old tracks or fresh one you discover from just released tracks with all you’ve already learn.
To me : When you start to learn a very vast area like Sound Synthesis you really need to cut the process in small parts, think the cuts regarding what is interesting or important to YOU and YOUR GOALS… We need to be efficient otherwise you can practice, learn and experiment everything without to produce something at some point. And of course what’s the point of taking years to learn something if you don’t produce something at some point.
Be careful with the hunger of learning ! it can be very addictive because it’s of course very interesting, but a musician need to understand he’s not a scientist… he really need to find his place and spend his time smartly.
and :