This tutorial assumes you have already

This tutorial is not finished (WIP)

Firs of all, make a new package called “block” in your root package (mod.yourname.modpackagename.block)
Then create a new class in your block package called “<what do I call this?>” that extends Block (net.minecraft.block.Block) (should it extend Directional Block) and give it a constructor “matching super” as reccomended by your IDE