It depends on what time the wedding is. You will need to pack up everything you will need for the wedding, shoes, jewelry, etc & a bag for that night. Sleep in late, relax, daven with kavanah.
Try to find time to something with your Mom & Sisters, get a manicure, pedicure.
It takes hours to get ready, hair, makeup, dress.
You will have your shomeret with you. She should be a close friend. Spend some time reminicing about your life. It is a life you will be leaving behind and will be building a new one.