Sometimes people who are splitting up go to court to have a judge make decisions for them, because they aren't able to reach an agreement themselves.
Children and teens usually don't have to go to court. Sometimes, the court will want to know your thoughts and feelings, and will appoint a lawyer for you to gather information from you and present it to the court on your behalf.
The court process can take a long time. Your parents may have to wait a long time for a court date, and they may have to go back to court several times, with a long wait each time. It won't happen overnight.