Hey so im really new to unreal engine and i wanted to make my ai move faster everytime the player picks up a key
i also want a sound when player picks the key , like a scream to show that the monster is faster
im currently making a horror game and its complicated lol , i will try my best to undestand 
Hey Kayzen! Welcome to the forums!
So you can do this multiple ways but I think the fastest/easiest/most direct for a beginner way is to use a dispatcher! The dispatcher will be located on the Key, and when it is picked up it should get all actors of class (it’ll grab any that are loaded) and send a message. That message will be set to Bind On Event in the enemy BPs, and then make an event that sets their max movement speed higher and uses a “Play Sound 2D” node. I grabbed this for you, it’s so useful I point people towards it on a daily basis.
thx i will go check that out