Hi, I see those videos as learning videos, not step by step tutorials (In my opinion there was way too much step by step in the AI learning video and it only concentrated on the very basics, so basically retold the quickstart guides, instead of talking about workflow and performance considerations and explaining the nodes available).
So you might wanna follow the behavior tree quickstart guide step by step Behavior Tree Quick Start Guide | Unreal Engine Documentation
Quickstart guide for EQS: Environment Query System Quick Start | Unreal Engine Documentation
And doc on AI Perception: AI Perception | Unreal Engine Documentation