Working with Object Storage

I have to create a project for my office that can store files for each student assignments such as pdf, doc, image and zip. My company want to use object storage. I have no idea of VPS or Object storage. I have to create a Laravel and host it in a VPS. That I can manage somehow. But the real issue is, how can be upload those files into object storage, most preferably digital ocean, download those files later and even delete those files if required? I have zero knowledge in Object Storage...