The quickest way to find information here is to look it up directly. On the left-hand side of your screen there is a Search box with two buttons under it labeled "Go" and "Search". Just type something into the box, like Math, and press enter or click the Go button. This will take you directly to Wikiversity's lessons on Math. There you will most likely find relevant answers to your question and, because this project is still growing, you can add your knowledge to the pool. If you have any problems, the rest of this article suggests ways to solve them.
If you're looking for a straight definition, our sister project Wiktionary is a good choice.
It's possible, due to a different skin or unusual display device, that the box will not be on the left. Just look around a bit, you'll find it.
If no such article exists, or if you accidentally press the Search button instead of the Go button, our search engine will do its best to help you along. If that isn't working for you, you could try an external search engine.