The yum repolist command will the repositories you have enabled. Refer to enable or disable a yum repository.

~]# yum repolist
repo id                   repo name                                           status
!base/7/x86_64            CentOS-7 - Base                                     10,072
!epel/x86_64              Extra Packages for Enterprise Linux 7 - x86_64      13,501
!extras/7/x86_64          CentOS-7 - Extras                                      448
!updates/7/x86_64         CentOS-7 - Updates                                   1,155

The yum repoinfo will display more information for each repository you have enabled.

]# yum repoinfo
Repo-id      : base/7/x86_64
Repo-name    : CentOS-7 - Base
Repo-revision: 1604001756
Repo-updated : Thu Oct 29 15:03:00 2020
Repo-pkgs    : 10,072
Repo-size    : 8.9 G
Repo-mirrors : http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra                                                                                                             =stock
Repo-baseurl : http://centos.mirrors.tds.net/pub/linux/centos/7.9.2009/os/x86_64                                                                                                             /
             : (9 more)
Repo-expire  : 21,600 second(s) (last: Sun Jul 25 04:52:49 2021)
  Filter     : read-only:present
Repo-filename: /etc/yum.repos.d/CentOS-Base.repo

Repo-id      : centos-sclo-rh/x86_64
Repo-name    : CentOS-7 - SCLo rh
Repo-revision: 1625867122
Repo-updated : Fri Jul  9 16:45:22 2021
Repo-pkgs    : 7,559
Repo-size    : 7.4 G
Repo-mirrors : http://mirrorlist.centos.org?arch=x86_64&release=7&repo=sclo-rh
Repo-baseurl : http://centos.mirrors.tds.net/pub/linux/centos/7.9.2009/sclo/x86_                                                                                                             64/rh/
             : (9 more)
Repo-expire  : 21,600 second(s) (last: Sun Jul 25 04:52:49 2021)
  Filter     : read-only:present
Repo-filename: /etc/yum.repos.d/CentOS-SCLo-scl-rh.repo

Repo-id      : centos-sclo-sclo/x86_64
Repo-name    : CentOS-7 - SCLo sclo
Repo-revision: 1605612561
Repo-updated : Tue Nov 17 05:29:21 2020
Repo-pkgs    : 816
Repo-size    : 275 M
Repo-mirrors : http://mirrorlist.centos.org?arch=x86_64&release=7&repo=sclo-sclo
Repo-baseurl : http://repos.mia.quadranet.com/centos/7.9.2009/sclo/x86_64/sclo/
             : (9 more)
Repo-expire  : 21,600 second(s) (last: Sun Jul 25 04:52:49 2021)
  Filter     : read-only:present
Repo-filename: /etc/yum.repos.d/CentOS-SCLo-scl.repo

Repo-id      : epel/x86_64
Repo-name    : Extra Packages for Enterprise Linux 7 - x86_64
Repo-revision: 1627176046
Repo-updated : Sat Jul 24 20:54:47 2021
Repo-pkgs    : 13,625
Repo-size    : 16 G
Repo-metalink: https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=x86_6                                                                                                             4
  Updated    : Sat Jul 24 20:54:47 2021
Repo-baseurl : https://mirror.genesisadaptive.com/epel/7/x86_64/ (29 more)
Repo-expire  : 21,600 second(s) (last: Sun Jul 25 04:52:49 2021)
  Filter     : read-only:present
Repo-filename: /etc/yum.repos.d/epel.repo

Repo-id      : extras/7/x86_64
Repo-name    : CentOS-7 - Extras
Repo-revision: 1623164282
Repo-updated : Tue Jun  8 09:58:04 2021
Repo-pkgs    : 498
Repo-size    : 920 M
Repo-mirrors : http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=extras&i                                                                                                             nfra=stock
Repo-baseurl : http://mirror.siena.edu/centos/7.9.2009/extras/x86_64/ (9 more)
Repo-expire  : 21,600 second(s) (last: Sun Jul 25 04:52:49 2021)
  Filter     : read-only:present
Repo-filename: /etc/yum.repos.d/CentOS-Base.repo

Repo-id      : updates/7/x86_64
Repo-name    : CentOS-7 - Updates
Repo-revision: 1627084757
Repo-updated : Fri Jul 23 18:59:50 2021
Repo-pkgs    : 2,542
Repo-size    : 14 G
Repo-mirrors : http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=updates&                                                                                                             infra=stock
Repo-baseurl : http://mirrors.wcupa.edu/centos/7.9.2009/updates/x86_64/ (9 more)
Repo-expire  : 21,600 second(s) (last: Sun Jul 25 04:52:49 2021)
  Filter     : read-only:present
Repo-filename: /etc/yum.repos.d/CentOS-Base.repo

repolist: 35,112