Well, I am so happy to read about your father's planning. I am the biggest lover of traveling and it's my passion. In my life, I have enjoyed many trips. Copenhagen is the capital of Denmark. It is the famous of its popullation and attractions.The Tivoli Gardens, The Little Mermaid statue, the Amalienborg and Christiansborg palaces, Rosenborg Castle, Frederik's Church, Børsen and many museums, restaurants and nightclubs are significant is the best tourist attractions. So, you will go with your father's without any hesitation and enjoy your time.