Factory reset and internal storage

I recently bought a tablet from my friend . I thought it was a steal of a deal untill I tried to download apps . My tablet will not allow me to access my internal storage or download any apps . What do I need to do to get to the internal storage ? It has a internal SD card as well as an external. I've tried numerous ways of goin about it. I don't even have an option as to where I want to save anything . And the worst part of all is if it dies or shuts off it does a factory reset everything .