Anyone know Redhat 8 in here that could help me with installing the right up2date client. I never used Linux before and I do not know anyone who uses it. Irecieved this message:

IMPORTANT MESSAGE REGARDING REGISTRATION WITH RHN:

The certificate used by up2date and rhn_register to communicate with the Red Hat Network reached its end of life on August 28th 2003. Users attempting to register with Red Hat Network will see SSL connection or certificate verification failures.

New versions of the up2date client that contain the new certificate are immediately available for download at:
https://rhn.redhat.com/help/latest-up2date.pxt

In order to register your system with RHN to receive updates, the
following command must be run as root after the above packages are installed:

For Red Hat Linux 8.0 and 9:
[root@localhost home]$ up2date --register

For all other variants:
[root@localhost home]$ rhn_register