I got no idea what im even doing 😅

So I recently watched a video by Kanokarob on youtube about adding custom strongholds to minecraft and it made me want to start making my own custom structures but I realized, I have got no idea what I'm doing. I've never done datapacks or jigsaw blocks but I want to learn. I tried to follow the guide that Kanokarob provided on PlanetMinecraft but I still was not able to follow that. Any and all help would be deeply appreciated.