What should I do to protect my concept of inventory business website? What should I submit?

Under US law, "whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor". 35 U.S.C. 101. So, in your instance, you would be protecting a novel and nonobvious process or method. More particularly, you want to protect the key process steps that you use on your website. As you must know, there are virtually no limits on the various particular lines of code (html or otherwise) that could be assembled to implement the fundamental algorithm of your process. So, claiming such an algorithm at the code level leaves others limitless opportunities to design around and still perform the algorithm. Accordingly, you should claim your process at the highest level of abstraction that remains novel and nonobvious. It is not necessary to include actual software code in a patent application. But, you must disclose enough about how you mechanized your solution that one of ordinary skill in the software art could practice the invention without excessive experimentation. Copyright is the vehicle for protecting your particular coded implementation of the website. As always, you should consult a patent attorney that is familiar with software patenting to properly advise you of your best strategies to protect your invention, whether through patent or copyright law.

If you want to protect the concept, you need to explore filing a patent.