Very little is available online in English, and all German birth, marriage, and death records were maintained by the local parishes until the very late 1800s.
Most of these parish records were recorded in old German High Script. The attached photo is the 1804 christening record for my 3rd great grandfather, Johann Theodor Wendel Kleinsteuber. (click on the picture to enlarge it)
This is why I recommend hiring a competent German genealogy researcher, to find the records, and present the findings in English. They belong to a licensed organization.