From 403 error to 500 internal server error

Question

I'm trying to install wordpress on a shared hosting (1and1), it's been 3 days i'm struggling and i give up, i've installed wordpress many times on other servers with no problem, first time on (1and1) and i think it will be the last.
The problem is that i uploaded wordpress, and when i try to access "mysite.com/wp-admin/install.php" or access "mysite.com/index.php" i receive the 403 forbidden error.
My root directory doesn't have a .htaccess file so i created one and put in it the values:

<Directory wordpress>
Order allow,deny
Allow from all
</Directory>

Then i get the: 500 internal server error.
I added those two lines, i saw them in the 1and1 help center:

AddType x-mapp-php5.5 .php
AddHandler x-mapp-php5.5 .php

and nothing happens.
I added those lines, saw them somewhere in wordpress forums:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

and nothing happens.
I'm using wordpress 4.4.1, PHP5.5 and MYSQL5.5
i just want to know what should i put in the .htaccess file to make this work?.