Wikipedia is a big place!
For a start, there are currently 0.3 million articles, the most extensive encyclopaedia in human history.
In addition to this, there are another 0.8 million supporting pages devoted to helping build the encyclopaedia (2.7-fold more than the articles)!
This tutorial will help you to get your bearings, learn how to find what you're looking for, and introduce you to a few of the most important pages.