The King's Indian Defense is a response to d4 openings.
There is nothing wrong with you looking at various openings as a beginner. Most people think that you shouldn't try to memorize openings however when you are just starting out. Rather, focus on the ideas of the openings.
So I have been recently studying some openings in chess for black as thats usually where I end up losing games, I'm not that good being only like 400 ish elo. So I came across a few studies on Lichess ( ik not the best site) but I saw that none of it states wether I can play the kings indian if white decided to play E4. It might be obvious I just dont really know, I dont even know i I shoudl reaslly pursue this opening as a beginner. Any tips ?