[SOLVED] Harry Potter Mod

Hello guys!

I need any possible help you could bring to me.
I want to make a Harry Potter mod but I don't know where to start.

First of all i want to make a Wand, of course. A ranged item that allows you to launch diferent spells, those spells are based on the potions/monsters effects what alredy exist on the game, like poison or whither effect. And if is possible, making a shortcut that allows you to swap bettwen all those spells, like pressing SHIFT+MOUSEWEEL. But i don't know how to do/code dat unfortunaly.

Second of all I'll make some mobs. Like the Hippogryph or a Troll, Pixies etc. I know how to do dat.

A fliying broom obviously and some other stuff like magic food or even clothes. That is covered too

So i just need help with the most important of the mod... Thnx for you support and help

*Update: For now I have done the monsters and a Wand as a ranged item, but unfortunaly I don't know how to swap bettwen spells and I had to do every single wand for each spell individually and later on do a book to select wich spell you want... As for the spell "Alohomora" I wanted to do something like opening iron doors with a projectile what do an redstone impulse with the procedure "When bullet hits block" but I don't know neither how to do that...

Another problem that I have is the projectile or the "spell", i use the procedure "when bullet hits X" + run the command "/effect @s minecraft:XXX". The problem here is if you shoot too close of the block/player/entity the effect also aplies on you. Theres any way to apply the effect only in the tarjet entity?