For a wedding to be celebrated in the Catholic Church one person in the marriage must be Catholic. The other person might be baptised in another Christian denomination or may not be baptised at all. It is not a requirement for a non-Catholic to become Catholic in order to marry a Catholic in the Catholic Church.
If you are a non-Catholic and planning to marry a Catholic, you may find it helpful to read about what Catholics believe. The Catholic Enquiry Centre can send you a free copy of the book, "Call and Response: An Introduction to the Catholic Faith" without obligation.
Wedding photo on Unsplash
17 October 2019