I have a question that border me because i dont now what to use and how to start

I want to build my hardware synth wit my idea & options.
Please I'm beginner in DIY so all help is welcome.
I have idea for cool synth but not vision-whole picture how to make one.
I dont understand how to create "Oscillator-MIXER-ENV-LFO-FILTERS-OUT etc..."
To real hardware PCB wit CPU or PIC wit pots, display and other components.
Everything i need to know is online in huge amount of information
but where to start to understand? Witch software & hardware i need?

What i need to learn?

I'm working in Jeskola Buzz from 1998 so i know logic what synth need.
For AIO, I know only for Axoloti, Bela, Synth Maker but what are other options?
How to make synth and put all to chip wit other components, that is my pain...

(Something like Audiothingies P6 & Micromonsta, MI Shruthi, PreenFM, SammichSID etc...)
Any advice and help is welcome.
Thank you all.