Download github content. Plugin folder structure should be ExileAPI/Plugins/Source/Follower with all of the files in this github located in that folder. Open the plugin on your follower, set follower name, match up movement hotkeys and start it.
This will follow a target character, pick up quest items, grab waypoints, etc. You'll still need to talk to NPCs to claim rewards but it makes multi characters running through acts much more seamless.