Topic: Tring to make brand new install & I get and error while installing the plugings

Hi.
There is no way I can do this correctly.

http://www.educafamily.es
Wordpress 4.5.2
brand new installation.
Only trying to install the theme and then follow the instructions step by step.
If I try to install plugins automatically, I get

INTERNAL SERVER ERROR
the server encounter an internal error or misconfiguration and was unable to complete your request..

If I try the installing plugins manually one by one… soon or later I get the same error. I change by FTP the name of the forlder of the plugin and sometimes it gets back to normal, but sometimes it does not. This behaviour happens with no matter which plugin I try with (ramdome).

Please… I think the details of PHP version and so on are correct. May I be wrong?

Please.. some help here