dose anyone knows how to make a nbt file?

so im making a minos prime mod but im new to the whole modding thing and barley know how to use mcreator or even make textures and so i looked onlien for nbt file for p-1 nothing at all stealing from the adrenila bosses datapack you say? i tryied but i couldnt cuz most of it was under ground and i dont know how to use the structuer block so dose anyone knows a solve for that like should i just look up a torturial on how to do so or a website that has ALOOOT of nbt files to chooise from?