An empty theatre is traditionally read as performing with no one watching, or a show that has ended. Dream books link it to loneliness, an unseen effort, or the calm after expectations fall away.
Does the traditional reading fit your dream, or did it mean something else to you?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.