The gpg command with the --gen-key flag can be used to create the GPG keyring.

gpg --gen-key

Or the --full-generate-key flag can be used to get prompts for additional data, such as the size of the private key, the expiration date of the public certificate, and the public certificate type (e.g. RSA or DSA).

gpg --full-generate-key

This command should create the hidden .gnupg in the users home directory, and within the hidden.gnupg should be the GPG keyring file.

[root@lab1 ~]# ll /root/.gnupg
14196878 0 drwx------  2 root root   58 Aug 14 13:55 openpgp-revocs.d
 9201150 0 drwx------  2 root root  110 Aug 14 13:55 private-keys-v1.d
 5537050 4 -rw-r--r--  1 root root 1986 Aug 14 13:55 pubring.kbx
 5537031 4 -rw-------  1 root root   32 Aug 14 13:38 pubring.kbx~
 5537032 4 -rw-------  1 root root  600 Aug 14 13:47 random_seed
 5537052 4 -rw-------  1 root root 1280 Aug 14 13:56 trustdb.gpg