need Help with custom projectiles

Im new here on the forum but i worked with Mcreator befor nothing big just some custom melee weapons ores ect.

im working on a mod that will add staffs and spell tomes to the game the idee is that the staffs provide an element and the tomes instructions for the element

for exemple you have a fire staff in your main hand and a projectile tome in your off hand now when you hold the right mouse button you fire a fireball

that flys in a straight line over a predetermint distance for the cost of 1 durability on both you staff and your tome and some xp points (not levels)

so i made a test staff a ranged item with no ammo cost and a force of 0.5 i tryed to add a line something like entityarrow.setNoGravity(true); but that didnt work

so i serched some more in the forums and found another solution with a custom entity however i dont have an option to add an custom enitity like a projectile or armorstand

only living entitys like animals or mobs so my question is how do i create a custom entity that can be used as a projectile as i plan for more projectile types then just a reguler one here are some more projectile types i plan on adding

spray projectile basicly like a flame trower

homing projectile like a shulker projecile but reflectable like a ghast fireball but when reflectet loses homing propeties

beam projectile like a beacon beam that fades into transparancy after max range

to sum things up

is what i plan to do  even possible with mcreator and if so how?

i hope you get the idee despite my terrible english skills