Help CenterDon't create a second KDP account, that is about the fastest way to have your account closed for life. This is in their terms and conditions and help pages.
If you want a different "Brand", Author Name or Pen Name, you just enter the author name / pen name that you want to use in the Author field in step one of the process in creating a new book.
Be sure to search Amazon and Google for the name you are about to use, to make sure it is not being used already beforehand. Before even making your book in the studio, because otherwise you may make the book, then search, and find out it is being used or maybe even protected by trademark.