> as a beginner using centos I‘ve a question about updates. > What it the right repo for getting all security and other updates? > http://mirror.eu.oneandone.net/linux/distributions/centos/7.6.1810/updates/ > for example? > A default install of CentOS is configured to use the "best" mirror for updates - "best" is a variable thing but usually comes down to a combination of geolocation, speed and load. When you do 'yum update' (which you should do regularly) the first thing you will see is yum determining which mirror to use. Note that it doesn't matter which mirror it is, they are mirrors, they (should) contain an identical copy to the centos.org master. In the absence of any other factor, you should just let yum do its job. P.