As someone who spent the better part of ten
Years reading and decoding Modular Synthesis
Before I could afford any modules I have
Simplified it to this.
Break modules down into these categories:
Audio Generator (VCO, Sampler)
Audio Modifier (VCF, VCA)
CV Generator (LFO, Seq, EG)
CV Modifier (Atten, Seq switch, Shift Reg)
Utility / Expander (mult, trunk lines)
Realize that most euro modules fall into more than one category. Start with the standard subtractive
Patch and move on from there. Use you ears.
It’s never that simple anymore but a good frame of reference to start.
Learning the Serge Color coding system will help too.
And of course, hands on experimentation helps
Most of all 