catch up on
catch someone up on (someone or something)
to tell someone the news of someone or something. (Fixed order.) Oh, please catch me up on what your family is doing. Yes, do catch us up! I have to take some time to catch myself up on the news.
catch up on something
1. to do whatever you have not had time to do I have to catch up on my reading.
2. to find out about something Most folks stop here for a cup of coffee while they catch up on the day's news.