How to get npc to chase other npc?

So I’m trying to make an npc to chase another npc and I wanted to do this in UE4 c++ but that did not work. I started off by creating a base class for the npc followed by 2 derived classes “Creature” and “Mercenary”. The creature is the one that’s suppose to be chasing the mercenary but it did not budge at all. I placed all the vector calculation within the tick function of the creature.cpp. The movespeed is set to 50 even tried with 1500 at the editor. Can anyone tell me what did I do wrong here?