Blank page after installing.

Hi,
Firstly, Please help me deactivate the Q&A plugin from your site. Sorry about that, my friend. I have installed our plugin and activate it to check your issue. To resolve this issue, you can try some following solution:
Solution1: I think hosting company was not using PHP5.
Find your .HTACCESS file on your server. It is a hidden file so make sure your FTP client (use filezilla) can view hidden files. Open up the file in your text editor and add the following line after the line # END WORDPRESS.

AddType x-mapp-php5 .php

Solution2: Create a New .htaccess File
From cPanel:

1. In the Files section, click on the File Manager icon.
2. Check the box for Document Root for and select the domain name you wish to access from the drop-down menu.
3. Make sure "Show Hidden Files (dotfiles)" is checked.
4. Click Go. The File Manager will open in a new tab or window.
5. Look for the .htaccess file in the list of files. You may need to scroll to find it.

6. Right click on the .htaccess file >Rename it .htaccess.bak. Alternatively, you can click on the icon for the .htaccess file and then click on the Rename icon at the top of the page.
   From the left-hand navigation menu in WordPress:

7. Click on Settings > Permalinks.
8. Review settings to be sure they are set up properly.
9. Click the Save Settings button.
10. Try reloading the site to see if the 500 Internal Server error has been resolved.

Still Getting a 500 Internal Server Error?
Increase PHP Memory Limit

If the error persists, try Increasing the PHP memory limit. Please refer to this article for more information on resolving the PHP Memory Limit Error.
To fix the problem, please modify the memory_limit line in php.ini to match this example:
memory_limit = 256M

Note: You can send me your FTP, I will help you check and fix it.
Hope this helps !