Information Gathering

Robots.txt

In the robots.txt (url/robots.txt) you may find some directories that are excluded by indexing, so you may try to access them and see their content.

Watch the http content of the folder that you found in the robots.txt:
curl target-ip/target-folder

You may see that certain target-folder are accessible and you can see the content, while others are protected or require credentials.
You may try a brute-force module to try to access them.