I am a girl, and I am afraid of being laughed at if I can't do anything well. How can I overcome this shortcoming?

It is not easy to overcome at once. I'll tell you a good way. Make more friends with confident people, and pay more attention to the way they treat others, especially feel their aura and temperament, gestures, eyes and so on. When you deal with something by yourself, tell yourself first that you can do it with confidence, and then look back and imitate their temperament and aura. Over time, you will form your own aura and show confidence between gestures. Of course, it is also important to improve one's own quality. Read more books, watch more movies, get in touch with some popular science knowledge and broaden your horizons. I believe I can do it. I wish you success! I believe you can do it!