Hey, you can try some websites like www.hotscripts.com to get help in coding.
Here go to this link take a good long look to see which of the scripts suits you the best.
PHP is strictly server-side. It doesn't upload files, it only receives uploaded files. See "Handling file uploads" in the PHP manual for more information on the server side of things.
Note that file hosting is against the Terms of Service. Depending on the purpose for the uploaded files, you could be headed towards a site suspension. Make sure you reread the ToS carefully.