In a couple of weeks, my parents’ church (United Methodist) is having a service to honor all high school and college graduates. In December I received my BA in history, and I was asked to attend, even though I am Catholic. I was planning to attend the Saturday night Mass and then attend the Methodist service on Sunday. Is there anything wrong with this?
These links should give you the answers that you need. If you have any further questions or concerns that are not answered by this, please contact Catholic Answers directly.