Why doesn't my MacBook Air have an Administration account?

Computer is MacBook Air (new computer)

Sequoia 15.2

I was setting up computer for minor. I was making settings for Screen Time - Content&Privacy. At one time I was informed that it is not a good idea to set my childs accound as administrator accound (or something like that). It asked if I would like to create a new account for administration. So I did that. I thought I was creating a new account for administrative purposes only. While creating that I saw an error message which disappeared later.

Later when I wanted to change settings in Users & Groups, it asked me administrations name and password. I entered the name and password for the administration account I thought I created. But it didn't accept it. Then I tried entering the name and password of user account I first created when I started setting computer up. It was also not accepted.

So I look at the list of users in Users&Groups and see that I have 2 accounts labeled standard + 1 guest account which is off. But one should be an administrative account?

So now I cannot make any changes because it doesn't accept administration info. I can't make new account into administration account because it asks me administration name and password and doesn't accept it. Can't reset password, cause same thing as above mentioned. I can't delete new account nor I can't add user also.

Can you please help me fix this?

Can it be fixed or should I start from scratch setting up the computer? If so, how?

Aili