Hiya. IDK what's up with anything on your screen. Can't help you with the nodes as IDK what they do, I'm not familiar with Dot Product, so I don't quite understand what that formula is meant to say. I have however just made my own angle calculator that uses logic to skip multiple steps of Pythagoras et al to create/find…
1. Get both vectors, and normalize them. 2. Connect the normalized vectors to a dot product. 3. Output the dot product to an arc cosine (NOT an arc sine!) I'm not sure offhand if the radian to degrees node is necessary, but otherwise that should be all you need.