I want to learn more about the ai behavior tree and I have a couple questions

I am fairly new to the AI stuff in unreal engine. I am currently trying to make a game that involves the behavior tree but I don’t know where to start. I want the ai to have a walking pattern and once the ai see’s the player, it will go toward it but when the ai catches the player I want it to steal the items the player collected and put the items back to where they were found which are found in a spawn source from the beginning of the level. Anyone have any ideas of how I can do this?