Always ask 5WH questions, not yes/no or "how much" questions. (Just in case they've not told you, 5WH is Who, What, Where, When, Why and How. Elementary in journalism, but often overlooked.)
Who is history is your favourite horseman, and why? (Mine would be Xenophon.)
How should someone explain riding to a friend who thinks, "You just sit there," and won't get on a horse?
What kind of training should a beginner's horse have, and how can a beginner know that the horse is properly trained?
Now I cold make up questions like those all day long, but you should be able to, too. Indeed, that's part of the assignment.
Additionally, when you have collected everything and are writing up your story, it should take you no longer than ten or fifteen minutes to write the story. If you agonise over the words for hours you are doing it wrong.