Synth sims are the cheap way to go. Cardinal is an open source fork of VCV Rack. It can be used standalone or as a plugin with your favorite DAW.

https://cardinal.kx.studio/

All the concepts are the same as modular "euro rack" synths. Voltage lines, oscillators, the works. You even use "wires" to connect everything.

All YouTube tutorials for VCV are generally applicable to Cardinal, btw.

If you want to go the DAW route, it should work with the free version of FL Studio. It's just much easier to do full tracks that way. However: FL Studio is not easy to learn and even less so when you are integrating something like Cardinal.

Edit: I apologize in advance if this post is the reason you fall into the money pit that is digital music.