How to solve open cart website crawling and indexing issue?

Hello Everyone !! How to solve open cart website crawling and indexing issue?

Robots.txt file excludes that page/folder by mistake.
URLs contain excluded parameters
Content that is inadequate or duplicate of other pages.
Not enough inbound links to trickle interest deep into the site.
No link to that page exists on an indexed/cached page.
Navigation that cannot be indexed

For more information you can visit :

http://searchengineland.com/solving-...problems-36856
https://moz.com/blog/how-to-fix-craw...search-console

There can be different reasons why search engine may not crawl a website. Some of the reasons are there might be crawl errors that is restricting the search engine crawler from crawling the website. The web page or the website may have been blocked for crawling by using robots.txt