Packages not available on fresh install

Hello,
Creating new post as first attempt seems to have failed. Apologies if first too got posted.
I come from deb background
when I install rhel, I expect package pointers in /etc/yum.repos.d
I don't see any.
Is there a way to fill that up?
when try install a group such as '[root@localhost marty]# yum grouinstall 'Development Tools'
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-
: manager
This system is registered with an entitlement server, but is not receiving updates. You can use subscription-manager to assign subscriptions.
No such command: grouinstall. Please use /usr/bin/yum --help
[root@localhost marty]#

Can someone help me installing 'Development Tools'?
TIA