What do apprentices in western restaurants usually do? Are you tired? Can you learn anything from dirty work?

The water bar is where drinks and fruit bowls are made. Apprentice means that you don't have any skills about water bars, so you mean an apprentice. When you learn to make those things, you can be said to be a bartender. If you are on-the-job, you will be fully mastered and proficient in almost one month. I hope this answer will help you, if you are not too tired to learn anything.