Could somebody please guide me to some REALLY Beginner Tutorials, please.

For me it was helpful to download and unpack an existing mod that does something similar to what I had in mind and then look around in the files, change some stuff and see what happens. So learning by example kind of and using an existing mod as template (but be sure to check the permissions on nexus!)
You can use Norbyte's tool to unpack a mod .pak file, translate the contained binary .lsf files into editable .lsx files and .loca localization files into editable .xml. And after some changes of yours use the tool to create loca and lsf files again and re-package the mod into a .pak file that's ready for installation. For installation I'd recommend
Bg3 ModManager. First thing you want to change is uuid, Mod/Folder name and author of the mod in file Mods/<ModName>/meta.lsx and change some folders to match the new Mod/Folder name. Can't say anything about grafic models and textures, but this could be a way to start.