The church screen is only for the most advanced users. This screen is to manage multiple churches in the same database. Normally, you will only have one church in one database and then this screen is unnecessary. However, you might see the need for a test church where people can come in and test using 'WorshipHHN'. Here you could create such a church or any other church if that is needed.
When you have more then one church, you must remember that each church is completely seperate from another church. There is nothing common between the churches. Therefore for each new church you must create everything from the beginning.