Installing Drupal

I've tried Drupal 8 on both servers: the first one that I use shared hosting installing works fine, but the other one that I have is a dedicated server and the installing fails. I don't have any issue with Drupal 7.

I'm using Apache 2.4, PHP 5.6, MySQL 5.5.55.
When I check the website page, it directs to the /install.php page. After that I'm choosing the language, standard profile, successfully passing the "Verify requirements", filling the database details and after couple of seconds it displays:
"Page not found
The requested page could not be found."

Hello Everybody, I want to learn Drupal, tried WordPress but I do'nt like it.
While installing Drupal 8.3.5 I get this error;
Error
The website encountered an unexpected error. Please try again later.
Drupal\Component\Plugin\Exception\PluginNotFoundException: The "comment_default" plugin does not exist. in Drupal\Core\Plugin\DefaultPluginManager->doGetDefinition() (line 52 of core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php).
Drupal\Core\Plugin\DefaultPluginManager->doGetDefinition(Array, 'comment_default', 1) (Line: 25)

Following are special install instructions for drupal if you are using debian9

1) Drupal7 is available in stable repository. so apt-get install drupal7
2) Create a mysql database e.g drpl, create a user e.g drupal and give all wights of that user for this datsabase
2) in browser run 127.0.0.1/drupal7. You will get two error message

ok, so we have a fully working copy of drupal and civicrm on a hosting server.

Moved all the files, moved the database, edited the /sites/default/settings.php file for the new database path, user and pass.

The main drupal site loads and seems to work, however, when i try to login......after a long time i get Bad Gateway in the browser and an error in the log:
Script timed out before returning headers: cgi_wrapper, referer: http://www.domain.org/

I have installed Drupal 8.3.5 locally (with MAMP) previously without any problems - when i tried to install to my online hosting server it fails on the first screen:

Hello, I tried to install 6 times Drupal 7 on a Virtual Box machine based on Ubuntu (tried with version 17.04 and 14.04) with different procedure for each one but always I get the same error in the install profile section of Drupal 7