Select"learn" and click on a bot that has a task (as long as it's battery isn't dead). The new one will "watch" it until it has complete one cycle of its task and then automatically start doing it as well.
you should add like a metal conveyor belt and a crude conveyor belt and it should put the items it carries into the next thing for example a general storage
and another suggestion, if you have alot of workerbots stacked on one spot, it could be a good idea to make it so you could see the names at the bottom right and select wich one you want