Cisco and Palo Alto Networks both have a Network Academy that are integrated into several high schools, and this is a great way to get a head start on a future career.
Many public libraries have free accounts with Rosetta Stone and with Lynda.com, and you can get a free month of courses from LinkedIn and just download all of the videos (I know I did :D).
Jeremy Cioara and Keith Barker also have a ton of very well made materials over at https://www.cbtnuggets.com/
At OPs age, I was devouring anything and everything I could get my hands on (and narrowly avoiding being arrested for getting into systems that I shouldn't have).
Things have been made far easier these days with virtualization and with free labs and easily accessible online training courses, so you don't even have to break into a network to start exploring a technology that you wouldn't otherwise see.