Infinity pop

I am looking to make 3 different design molds, a cube, pyramid, and star. Each will have little shapes on each side you can pop out. Kind of like a pop-it. I am just looking to make the molds. So that I would be able to pour silicone into them, to make them. I know my drawings aren’t anything amazing they are just sketches. I am thinking of making two different molds. An outside mold and an inside mold. I want to use flexible filament so I could put one side of the mold into the other. So the outer mold would need an opening for that reason.