Somewhere between 80-90 percent of all first dates occur after two people show each other a little attention. People typically do not ask someone out that they do not know. So if you want to ask someone out, it's a good idea to try talking with the person first or, at the very least, establish a little eye contact. In general, most people can get a feel for whether someone would want to date them or not. If you do not know whether the person is interested in you, take a little more time and try to interact with them before you ask them out. Do they respond to your attempts at communication? Do they flirt with you? Do they smile at you? Are they open with you? Answer these questions and you will know if someone is interested in you.