[xyproto]

Established companies that are not startups typically provides more guidance, but also less freedom. They may also offer more pay for the first couple of years, until and if the startup becomes a success. You have to have some tolerance for byrocracy and more+longer meetings, though.

I think one way of finding a mentor is to ask someone that you want to become more like, that typically work as a manager or in a position where they want people to succeed, to mentor you. Keep asking people until you get a "yes". This is probably also easier in a larger organization.

Best of luck.