The Dwarf Fortress UI can be intimidating. Key elements include the main game screen displaying your fortress, the sidebar for menus (designations, building, stocks, etc.), and the top-left corner for important alerts and messages. Learn to use the keyboard shortcuts, as they are crucial for efficient play. The 'k' key for looking, 'd' for designations, and 'b' for building are among the most frequently used. Don't be afraid to experiment and consult the in-game help ('?') often.
