Steve Jobs was connected: By being raised in Silicon Valley at just the right time. He even had a story (who knows how true it is) of him as a kid looking up Bill Hewlett in the phone book and asking about electronics parts (a frequency counter IIRC) and Bill not only got him the part, but gave him a summer job.
As for business, many successful tech entrepreneurs “learn” it either as they go or by bringing on business experts, but not giving them full control. For larger examples of the latter, see Eric Schmidt as the “adult in the room” for Google, Sheryl Sandberg for Facebook.