Do you have anything.

什么 means what 吗 is a common interrogative pronoun meaning “yes or no”. We always put 吗 in the end to make it a question. 你有什么事吗？Literally it means “what matters do you have”. Most of the time, It is a general inquiry. For example, when I make a consultation call, I will hear such a sentence meaning “what can I help you?”. And sometimes it contains a tone of impatience. It’s more like ”what’s wrong with you?”.

the meaning of“你有什么事？”and “你有什么事吗？”are the same, but the word“吗” can soften the tone.

Thanks so much

yes, you are right. 你有什么事? can also mean 'what's up?' but this version sounds a bit more serious than 你有什么事吗？. '吗' can soften the tone and sounds better. Without it, depends on how you say the sentence, it shows the asking person a bit annoyed.