Yum issue

Hi there:
I installed RHEL Enterprise version 8.1 last week, and it worked fine.

I am installing Oracle 11GR2.

In order to install Oracle 11GR2, I have to run rpm to install some packages and in order to set xterm*, xorg*, xclock and xauth i ran the following command:[root@localhost ~]# yum -y install xterm* xorg* xclock xauth

and received the following.
Updating Subscription Management repositories.
This system is registered to Red Hat Subscription Management, but is not receiving updates. You can use subscription-manager to assign subscriptions.
Error: There are no enabled repositories in "/etc/yum.repos.d", "/etc/yum/repos.d", "/etc/distro.repos.d".
[root@localhost ~]#
..................................................
I have checked the date and time as suggested by one memo as follows and it is set properly:

[root@localhost ~]# date
Mon Mar 30 16:45:20 EDT 2020
[root@localhost ~]#
.......................................................
Yum update gives me the following:

[root@localhost ~]# yum update
Updating Subscription Management repositories.
This system is registered to Red Hat Subscription Management, but is not receiving updates. You can use subscription-manager to assign subscriptions.
Error: There are no enabled repositories in "/etc/yum.repos.d", "/etc/yum/repos.d", "/etc/distro.repos.d".
[root@localhost ~]#
.............................................................
Yum repolist gives me the following output:

[root@localhost ~]# yum repolist
Updating Subscription Management repositories.
This system is registered to Red Hat Subscription Management, but is not receiving updates. You can use subscription-manager to assign subscriptions.
No repositories available
[root@localhost ~]#
...............................................................
Force ReRegistration provides me the following:-

[root@localhost ~]# subscription-manager register --force
Unregistering from: subscription.rhsm.redhat.com:443/subscription
The system with UUID 09683cf6-62a5-4b2f-8aa0-45d4cb24a87c has been unregistered
All local data removed
Registering to: subscription.rhsm.redhat.com:443/subscription

[root@localhost ~]# subscription-manager register --force
Username: blf2vkr
Password:
The system has been registered with ID: 77865d01-73b5-45c5-b3a5-074c92c597db
The registered system name is: localhost.localdomain

......................................................
PLEASE GUIDE WHAT TO DO. My two Email Addresses are: riyazm@gmail.com
blf2vkr@gmail.com

REGARDS AND THAKS IN ADVANCE.

blf2vkr