Drupal requires you to enable the PHP extensions in the following list (see the system requirements page for more information):

The directory sites/default/files does not exist. An automated attempt to create this directory failed, possibly due to a permissions problem. To proceed with the installation, either create the directory and modify its permissions manually or ensure that the installer has the permissions to create it automatically. For more information, see INSTALL.txt or the online handbook.

The Drupal CMS installer requires that you create a ./sites/default/settings.php as part of the installation process. Copy the ./sites/default/default.settings.php file to ./sites/default/settings.php. More details about installing Drupal are available in INSTALL.txt.