How do I look up a question that has already been asked/answered in the general section, so I don't waste my time asking the same thing as someone else?

I wanted to ask a question about tumblr, but I would rather look and see if there are already question’s people have asked under either the general, or social section.
When I tried to type tumblr in the search bar at the top of the homepage, only google results came up.
So, is there a search button, or bar locating somewhere within the General Section and I’m just missing it?
Or is there no way to look up already asked questions?