When someone asks you “wyd,” they are asking what you are doing. The best response to this question depends on the context in which it is asked. If you are at work, you might say that you are working on a project. If you are at school, you might say that you are studying for a test. If you are at home, you might say that you are relaxing or watching TV.
It is important to be honest when answering this question. If you are not doing anything, you can simply say that you are bored. There is no need to make up a story or try to impress the person asking the question. Just be yourself and they will appreciate your honesty.