Hi Jasmine! Welcome.
I understand the difficulty of considering polygamy (polygyny) in coming from a Catholic background. Catholic teaching is among the most dogmatic in the world and not open to discovery of truth beyond what has been archived by that church. New discoveries of old truth is very overwhelming. Julie's advise is the best way to get started. Just reading the posts here can seem like a daunting task, but dig in and read with an open mind. Not everything you read here will be correct. We are a diverse group of people and most of us are in the process of continued learning. As you read, ask God to lead you and give you understanding. He will help you. Get a good Bible and check out the references you find here. Also get a good dictionary, that too is very helpful. Oh, before I forget, HAVE FUN DISCOVERING!!!