I cant install it on bluehost

I tried to install it on bluehost and I imemdiately get errors…why do you need special server to install it?

I get these errors

The site is currently offline due to encountering an error. If the problem persists, please contact the system administrator.
System administrators, check server logs for errors.

Any idea what to do? I have 5.6 php version on server…

I get this error now

We have detected 1 major problems. You must fix them before continuing:

PHP version 5.6.x requires the PHP configuration directive always_populate_raw_post_data be set to -1. This is handled automatically by the .htaccess file when using Apache and mod_php5, but must be set manually in php.ini for other server configurations. Please add ‘always_populate_raw_post_data = -1’ to your php.ini and restart your web server.

How to add this.???
I only have

always_populate_raw_post_data = ON, so should I change it to -1 or ???