I would like to create an item that when right clicked with, it will start to light up the area around you.(Like a lantern)

What would I need to put into the onRightClick method to make it switch between the off item and on item?

Also how do you add a light value to an item?

Also it's a coremod.

I do believe it isn't. However, i have not managed to make headlights for my locomotive

Which sections of dynamic lighting should I be looking at? I know I would have to create an updater to make the light emitted follow me but since the mod has several different light emitting things, I'm not sure where to look.

One way of doing this is by creating an invisible block with a set light level, and then having this block be created by the item every few ticks (don't do it too often, lighting eats memory like there's no tomorrow) and have the block remove itself after the same number of ticks. This isn't too hard to implement, but there are probably many more efficient ways of doing this (in terms of memory usage) but this method is fairly easy to do.