How to Botnet

So lets say ive created my own little botnet with pcs that I own and some family ones..

What can I do with them...

Lets say if I have about 30 of em.. then if I want to run sonething ill have to open each session seperately and run commands on each of them??

And can I do something like when I open the payload on a pc.. the persistance script is automatically run?? And if I had my own scriot that would autorun too??

And exactly what all can I do with my botnet?? Like wpa cracking but how??