I'd envisage, what with the diversity of the crew, that perhaps they could use their spare time making a zero-gravity pron film. They could start with Christina Koch (great pron name) getting cold and the other astronauts attempting to warm her up with their own large rockets.
Back to reality, in that Apollo 13 only went around the moon because of a fault with the module. This time, Artmeis2 is all prepared , with cameras and monitoring equipment to get detailed information from the Dark Side. There are many big questions to try and get answers to. Is there any indicators that water was ever present ? Did the moon originate from a large collision with Earth ? Which crater does the Soup Dragon live in ?
The moon is the only realistic object for mankind to do return trips to. Going to Mars, with current technology, would be a one-way trip.