Next, buy, don't borrow, Paul Johnson's books A History of the American People, and, Modern Times.
Read both books.
There's LOTS more you need to read, but if you can get through those two, come back and tell us, and we'll tell you what to do next.
If you're as intelligent as you seem--seeing how you came looking for answers and didn't just sit there and take what's being tossed at you--you'll probably be able to figure out what to do next.
Good luck.