trouble with the WP-Folder location

once I enter by ftp the server that I rent one of the folders is public_html, however the main website is not there but inside another folder

in order to be able to access the wp-admin folder I had to create a folder in the main website folder and run it from there.

It all went well, but when I try to install a plug-in or theme, I put the access info for the ftp (or should I put for the mySQL database?) but then it says it cannot find the wp-content folder

any recommendation on how should I proceed?

thanks a lot