If you are starting out, I would suggest creating a simple blog application. Keep it simple until you get strong in you php coding. A simple blog application will require php and mysql. You can even add jquery to make it more dynamic.
i need something a bit simple coz im not yet perfect coz i want to create a web application but not knowing what kind of application. and the project is supporsed to be in line with the organisation im doing my internship in and im doing my intership at a varsity so um supporsed to create a project that can be used by the istitution.
You could do a project tracking system. That should be easy, and could be used with every departement. The tracking system would track you, projects, people working on the projects, updates to the projects, time schedules to the projects, track file information, track user edits, track due dates. It would not be hard to create. This would be something you could use and build on for future projects as well.