I do not find anyway to delete a “Main Character.” Does anyone know how to do that?
You should be able to rename or reassign the Main Character, yes? If you mean get rid of the Main Character entirely, you, uh, can’t. If you’re trying to write some sort of explorative, absurdist venture without a Main Character, you can certainly do that, but Dramatica won’t help you. 
I don’t think I explained the problem clearly. I created a case of characters, then I created a main character. Now I have a Main character and an ordinary character by the same name. The problem appears further ahead in the process when I have two characters with the same name. I think I should have created a regular character and later designated that character as the main character. Is that right or wrong. If wrong, how should I have created a main character.
Pretty much what @actingpower said.
If you go to the character window, you should be able to switch the regular character to be the Main Character. And then you can delete the other one.
Thank you very much.