How do we move a character using AI not by input in 3rd person blueprint based project?

[Nawrot]

this is advanced, (and may be outdated a bit):
https://docs.unrealengine.com/latest/INT/Engine/AI/BehaviorTrees/QuickStart/index.html

this is most beginner ai tutorial i know about:

A new, community-hosted Unreal Engine Wiki

You could use this from marketplace:

AI Behavior Toolkit in Blueprints - UE Marketplace

However i would recommend following first two tutorials before buying modules from marketplace.

also google for “unreal blueprint character AI” you get plenty of tuts.