Missing Repositories

Hello i have been having a problem with my Cent OS 7 installation, i seem to be missing a lot of packages now i mean like im unable to install apache2 and other similar packages that i need to get rutorrent up and running ive tried adding additional repositories. Any advice would be much appreciated. (oh please note im very familiar with the way in which you add repositories in debian but not at all in cent os.)

rpmfusion is a thing
http://rpmfusion.org/Configuration
everything you might possibly need should be in there

there's also this epel thing, but with what little i used centos i just added rpmfusion and had all of teh packages
su -c 'yum install epel-release'

As far as how to add manual repo's you can add .repo files to /etc/yum.repos.d/
they should be formatted as

[repository ID]
name=repository name
baseurl=url, file or ftp://path to repository

thanks a heap really appreciate the advice

Its already in the CentOS repos.

To install Apache.

yum -y install httpd

to enable

systemctl enable httpd