Custom Block Help

Hi so I'm working on a warrior cats mod and I've made my first block that uses a custom model for it using block bench a nest. The block is smaller the a standard size block in every way and craters in the middle, I'm wondering if there is a way to have it so you can't walk through the solid parts of the block but can walk through the transparent parts where nothing is there? This will be especially important as it's used like a bed but when you are on top of the block you hover well above it. TIA