i need help making my first datapack

so im trying to make my first datapack just to try it out and i cant seem to get any of it to load any idea why ? im trying to make it so you can craft xp bottles but when you craft it remove 11xp from player but if player has < 11 then tell them they cant craft and im using an extenshon named spyglass on vscode and thats not helping me i know how todo this with spigot or papers api but im trying to turn some of my stuff into datapacks since i feel like that might be better for me for some of my stuff that i do