It’s easy to find the pages indexed in Google for your website. Simply go to the search bar and type the following query:
In the upper left corner of the results page you should see “About [some number] results”. You should go through these pages and identify which ones the search engine does not have listed. This may be due to a duplicate content issue, or due to the fact that the search engine may not see them as important enough. If you have page missing from the index,p make sure they have pages linking to them, even if they are internal links for now. You should also make sure none of the pages lead to a 404 error.
The same query should work in most major search engines.