What should I learn about AI in UE4 for bots in a shooter game.

It’s a simple project, the AI will inherit everything that the player character can do, animations, abilities, ammo & heath etc. Basically a copy of the main character, with different skins. I’m just beginning with AI and would prefer taking a simple and a functional approach, without going through everything related to AI.
Which parts of the AI system are essential and which are not, for simple shooter bots, not unlike we saw in Battlefield 2?