What kind of new but I don't really know what to do even

Yeah I know it's about making factories, i understand how gears work and am working on building a steam engine, but I don't know like what actual factory is there to build and what is there to farm what is there to automate, it doesn't feel like I really feel like there is anything in specific to make an a factory for, idk how to explain it?I'm sorry if i'm being obtuse, the idea of creating a working factory in minecraft is really appealing, but now that i'm here, I don't really know where to actually start