“Be careful not to spend your time having parties and getting drunk or worrying about this life. If you do that, you won’t be able to think straight, and the end might come when you are not ready.
Daniel did not want to eat the king’s rich food and wine because it would make him unclean. So he asked Ashpenaz for permission not to make himself unclean in this way.
You were taught to leave your old self. This means that you must stop living the evil way you lived before. That old self gets worse and worse, because people are fooled by the evil they want to do.
King Nebuchadnezzar gave the young men a certain amount of food and wine every day. This was the same kind of food that he ate. He wanted them to be trained for three years. After that they would become servants of the king of Babylon.