I recommend this series and this creator: https://www.youtube.com/watch?v=9wJcIM3zfkw&list=PLRDkUKkyMRU_Kr2yncnDV_HkP-5r07yDW&ab_channel=PlayUGC
https://www.youtube.com/watch?v=2au1e0GqoE0&t=1337s&ab_channel=PlayUGC
As far as learning all the functions you have available, it’s good to just read through the entire digest files (fortnite.digest, verse.digest, etc.) and take notes for yourself for what seems the most useful for you, build a cheat sheet that you have open while programming. It’s a lot of lines but after an hour or two you’ll have a lot more tools at your disposal