the datapack is supposed to go into the minecraft world folder instead of the mods folder, otherwise it wont work. If you are wondering where that is it's in the edit button when you click on the world and then you click open world folder, then take the datapack file, and insert it into the folder named "Datapacks", if it still doesn't work, then try to extract the file from the zipped folder.

Fabric itself is just a file for the ability to use mods, you need to have the file inside of the mods folder and same with the mod you want to have on, I personally suggest a mod menu for it as well as the mod so you are able to keep track of which mods you have on, and you will be able to configure them.
But then again you really don't need fabric or any mods for this.