Why do I need form 3800 for general business?

Form 3800 is for reporting business credits. It could contain an entry from the previous year even if you don't have any business credits in the current year. It sounds like you are using the desktop version of TurboTax and if so you can use the Forms icon on your menu bar to bring up a list of forms in your program. If you click on the Form 3800 you can see what numbers appear on it. If you click on any number and "right click" your mouse you will see an option for "data source" which will tell you where that number came from. You can search backwards in this manner to determine where the numbers on most forms originated from and you can usually adjust the source number as is necessary. You may be able to remove numbers appearing on Form 3800 in this manner and that may allow you to delete the form.