Hi@akhtar,
By default, RedHat has one ISO file. Inside this, you can find lots of Softwares. You just need to create one repository for these Softwares inside /etc/yum.repos.d/ folder.
[root@localhost ~]# vim /etc/yum.repos.d/yum.repo
[dvd]
baseurl=file:///run/media/root/RHEL-8-0-0-BaseOS-x86_64/AppStream
gpgcheck=0
[dvd1]
baseurl=file:///run/media/root/RHEL-8-0-0-BaseOS-x86_64/BaseOS
gpgcheck=0
To check the yum server is installed properly or not, you can use the yum repolist command.
[root@localhost ~]# yum repolist
Updating Subscription Management repositories.
Unable to read consumer identity
This system is not registered to Red Hat Subscription Management. You can use su bscription-manager to register.
Repository 'dvd' is missing name in configuration, using id.
Repository 'dvd1' is missing name in configuration, using id.
Last metadata expiration check: 0:03:39 ago on Mon 27 Jul 2020 11:11:38 PM IST.
repo id repo name status
dvd 4,672
dvd1 1,658