“Knowledge itself is power.”
Sir Francis Bacon, or his secretary, Thomas Hobbes, is credited with the above quote, written sometime in the 17th century. This quote, like most information, can be found online. Ham radio topics like exam preparation, skill training and technology collaboration are easy to find with a few clicks. This page has some basic links but you’ll find plenty online to absorb.
ARRL’s website is the best place to start. “The League” provides a wealth of information on their page, much of it open to all. Some information may require creating an account and/or joining the league.
Exam prep will include some math and some electrical engineering to start (the more the merrier). Khanacademy.org provides excellent lessons on both topics (among others). Their site is free but they accept donations in support of their mission.
The principles of radio operation and signal propagation are the same now as they were in the late 1800’s. Older instructional films are available online that are informative while also revealing how earlier operators thought about radio, its value and necessity.