I am new to scripting, but I've been making really basic addons for my friend groups realms for many, many years now. Mainly making Unique armors and weapons for them to find through quests or cool locations (I'm pretty much a Story GM for them). Recently, I wanted to upgrade my game by learning Blockbench and Scripting. Blockbench is straight forward, but I have no idea what I'm doing with JavaScript or the Scripting API period.
I mainly use a mobile app (Minecraft Addon's Maker) for everything that I do, because it's easy to use and I've always worked better on my phone than my PC, and usually work on it while I'm out and about. I plan to at some point switch to PC for creating addons however. Sorry if this is a silly question; or because I'm using a mobile APK to make addons. Any and all help is appreciated.
The plan (for now) is to make a custom Spear/Glaive weapon that when used (mid-air / without a chestplate equipped) you will get an elytra, as well as activate the Totem sound and particles. I don't know if that's really advanced, or basic.
I also wanted to make a crossbow that when fired does a Warden sonic boom that fires out in a straight line for about three chunks, but needs a super long reload time (roughly 15 to 35 seconds, depending on balancing I wanna do for it).