Getting ahead of myself here- downloaded a book and not to the end of it. But are there specific “paths” one must work or is it more like you can create things for yourself in a hypnagogic state that then manifest in your reality?

Pathworking, at least how I understanding, is meant to do two things: help build a relationship with the spirits/forces you are working with and to acquire power for change within the tradition of that system. You can achieve your goals without going through the system in its entirety but going through it (such as working through a grimoire gradually as opposed to just a section) may add an extra punch to the working as you have gotten deeper into the immersion process.