INCREASE YOUR KNOWLEDGE!
Here you will gain some free insight into self-publishing. This may help answer some of your questions.
Technically your writing is copyrighted as soon as your print hits the paper. However, it is always recommended to get your material copyrighted to prevent any possible issues after distribution. Copyrighting requires the completed material to be sent in when requesting copyrighting. If any changes need to be made after submission, a whole new application and upload will need to occur.
ISBN & BAR-CODING
For every book you wish to distribute to the public, you have to have a separate ISBN. That is one for an E-book, soft-back book, hard-back, etc.
A bar-code is needed for every printed book to be sold through online and brick-and-mortar stores. This is not necessary to have for e-book online sources.
These numbers and bar-codes are etched in stone once they are assigned to your book. Any changes or new editions will have to be assigned a new ISBN and/or bar-code.
When you want your book distributed through brick & mortar stores, your book needs to have a side binding with title and name to display books in their stores. Just think about when you visit a library or bookstore; several books are lined up beside each other.