Civilization is a video game that plays like a board game. It's complex, rich, and wonderful. Make sure you're playing 6th Edition with the Gathering Storm pack. These are some resources/guides that I'm working on, along with other helpful references.
Note: Everything on this page assumes you're playing with Gathering Storm. If you aren't, you should fix that; it's arguably the only "full" Civ experience.
Errata: The Replaceable Parts eureka is actually "Have 3 Line Infantry." For Siege Tactics, it's "Have 2 Trebuchets."