Figuring Out Structure/Jigsaw Blocks (1.21.5)

This is my first time attempting to use structure/jigsaw blocks, and my brain is absolutely cooked trying to figure this out. I've been attempting to follow this guide (https://www.planetminecraft.com/blog/custom-structure-gen-documentation/) but ended up getting lost as soon as the JSON files started coming into play. I am not trying to automatically generate these structures in the world at the moment, I'm simply trying to get them to work when I place a structure block or use the /place command. Would anyone be able to review this datapack setup and tell me what I'm missing? (I apologize if it's something stupidly obvious, I'm new to using structure/jigsaw blocks). I currently don't have anything in the template_pool folder because I simply don't know what to do there. I also do not have the structure or structure_set folders in the worldgen folder as I assumed those were only if you were trying to randomly generate the structure in the world. I've attatched the datapack alongside some screenshots. I would appreciate any help in figuring this out because I am completely lost. I feel like once I actually see this working the first time I'll be able to reverse engineer it for more complex structures from there, but getting to that point is a struggle for me. Please let me know if you need any more screenshots or information than this and I will try to get back to you right away.