Problemas com instalações no ubuntu

Galera,

Sou nova com linux/ubuntu e estou com problema em algumas instalações.

No momento estou tentando instalar o framework php e estou com o seguinte erro

file_put_contents(/home/cintia/.composer/cache/repo/https---packagist.org/packages.json): failed to open stream: Permission denied
https://packagist.org could not be fully loaded, package information was loaded from the local cache and may be out of date

[Composer\Downloader\TransportException]
The "https://packagist.org/p/provider-2016-01%244bf1cbf2e1a662285770db0d971
7403e5605fc875a000c35f997d346896b9b5b.json" file could not be downloaded (H
TTP/1.1 404 Not Found)