Learn Swedish: När har du mötet? - When do you have the meeting?

This is because of the Swedish "V2 rule", which dictates that the verb is usually the second piece of information in a sentence. Since the question word När (when) takes up position 1, the verb har (have) must be in position 2, placing du (you) in position 3.

The English translation says "When do you have", but there is no word for "do" in Swedish. Why?

Swedish doesn't use "do" to make questions like we do in English. Instead of saying "When do you have", you just say "When have you" (När har du).

Why is there a -t at the end of mötet?

The -t at the end is how Swedish says "the". The basic word for "meeting" is ett möte. Because it is an ett-word that already ends in a vowel, you just add a -t to the end to make it mötet (the meeting).