I am 30 years old and still single. Will people look down on jokes? How can I find my favorite girlfriend?

No, because marriage is generally late now, and the ratio of men to women is unbalanced, with more men than women. The cultural knowledge of modern women is also very demanding. The news often reports that the divorce rate is high and many women are afraid to get married. You can find a professional reference or get to know others by participating in activities. And introductions from relatives and friends.