Ask isn't really like Facebook, so it's not really designed for finding or adding "friends". However if in the course of asking or answering questions, you find other members on the site, whose content you find interesting, you can click on their username, which will take you to their profile page. From there you can click on the "follow" button, which will allow you keep an eye on the content that they post from your "Connections" link on the left side of the page.
This isn't facebook. This is Ask.com where all you do is ask and answer questions. You can follow people. I guess that's a good way to make friends. Commenting on answers and talking to people is a way to make friends over the internet, I guess