Permissions with files

I bought a new computer and it came with endless os 3 installed. In the app center it has the bluefish to install and it installed correctly, but when I try to access files in the directory it cant find them. If I open a file a .php file directly with bluefish it doesn’t save the file in the same place it saves the file in another directory.

For example I’ve tried to install notpad++ from a repository and installed correcty, but when I try to acess a file it says it doesn’t exits.

How can this be solved ?

Thank you in advance for your help.