"Hai un cane?"
It is pretty easy as long as you don't compare it to the way questions are structured in English, because that will get confusing:
- Take an affirmative sentence (Hai un cane)
- Add a question mark (Hai un cane?)
With interrogative pronouns and adverbs, the situation changes a bit:
- Take an affirmative sentence (Tu hai un cane)
- Rule of thumb, place the pronoun/adverb at the beginning (Chi ha un cane? Perché hai un cane? Cosa hai?)
That's a good way to start, but you will find other ways of forming questions as you go along :)