Sorry! But how do I search for questions to see if they have already been asked?

I know this is a stupid question, because everyone on here seems to know the answer already, so I guess I am just deficient in that area… But seriously, how do I search for previously asked questions? Is there something besides the “See all topics” to find specific questions? I looked around on the site before asking by clicking the links, but I still didn’t figure it out :-/