Is the subject line the problem? You want to create another admin account?
When you installed the moodle, you had to setup the initial admin account ... default login was admin - unless you changed it.
To create another admin level account, one has to create another account - manual authentication - first. So login as the admin level user you know and go to Site -> Users -> Permissions -> Site Admins. There you can pick an account from the right side and make them admin level.
Couple of things since you are CS ... explore command line admin of the moodle. There are quite a few 'cli' directories in moodle that contain command line only scripts. The main one is in code/admin/cli/
Moodle is an iceburg ... lots below the water line!
Suggest you install moosh - a command line only utility.
https://moodle.org/plugins/view.php?id=522
As you know, moodle is backend ended by a DB. Is yours MySQL or MariaDB? If so would also recommend the install of another tool called MySQLTuner - a perl script - helps tweak DB server.
https://github.com/major/MySQLTuner-perl
And do consult Moodle docs before asking questions ...
https://docs.moodle.org/405/en/Main_page
Most of the time, answers to questions are there.
When reporting a problem/issue and seeking help, probably a good idea to provide some info about your moodle server setup ... like version of Moodle, version of PHP + extensions, DB and it's version, Linux distro? (which), etc., etc.
If you are into AI, use caution with what AI's find/suggest about moodle server admin.
'SoS', Ken