The YouTube videos can be misleading. It is possible to get wonderful sounds with a few modules. But one has to choose them carefully and connect them in particular ways. One doesn't want only one wonderful sound, but many different wonderful sounds, and that might require more than a few modules.
I don't have direct experience with any of your components. I don't think that you can do anything interesting with the VCA, the Seq, Clouds, and the mixer by themselves. They're not junk, but they wouldn't work in one of those videos, not by themselves. They can be used to enhance what the Neutron does, but only if you know how to use the Neutron. You can avoid the constant sound of the Neutron (changed only by turning the tuning knobs) by giving the oscillator some pitch information via MIDI. A keyboard would be the best learning tool for this. You can use a computer or tablet, but it is more complicated to set up.
The link below my messages is my write-up of one possible introduction to modular synthesis. It doesn't talk specifically about your devices, but the concepts are transferable. You can find sections on the Neutron that correspond to things I talk about, and see if you can duplicate the results. If it is not to your taste, there are many other such resources.