Getting started in number theory
Getting started in number theory
When I started learning about math in highschool, it was somewhat daunting given the amount of information and where to go! Below are some links and explanations of how to use them
The art of problem solving is an excellent starting point, in particular, their acumulus problem system. For any given concept you don't understand, they have documented problems from competition with solutions. When starting on the art of problem solving acumulus program, learning number theory, it is very easy to get a feel for the problems and then grow from there. If you have any familiarity with Khan Academy, it has a similar progression system. Additionally, the AoPS wiki is well-written, with general explanations of concepts.
When practicing for competition math in high school, I found that AoPS provided the best way to practice and get situated with competition math. Additionally, the books are good resources; however, I have never used them.
While often derided in school for factuality, any number theory concept you want is probably written up by professors in great detail, almost too much detail... Since such high-level mathematicians write Wikipedia, it effectively serves as a graduate reference in mathematics. Often, this is beyond what one can understand at the moment. However, for any sufficiently large article (e.g., chinese remainder theorem or modular arithmetic), there should be explanations that are more accessible to someone just starting.
When personally starting on my math journey, I found it was beneficial to mull over the definitions I didn't fully understand on Wikipedia. A math professor once said, "There is no understanding in math, only familiarity," which holds the most true for someone just beginning.