Make an Upload Script that someone else can view

Hello there,

I want to make this website where let's say, Person 1 uploads a file. Then the admin, let's say Person 2 can view that file using a username and a password. Then Person 2 can review the downloaded files and can delete it if it's inappropriate.

As well, when someone signs up for an account, how could make the account have a default password, let's say "banana", then maybe at a 30-day period, there could then be an option to change the password once to whatever you want.

Sorry if that seems too confusing, it's just that I'm gearing this up for a great website!

EDIT :: Someone posted saying "Fantastic!", but I actually want to know how to make it. Sorry if I didn't word it properly, apologies.