I can't remove admin rights from an account on my MacBook Air

Yes, I understand that a lot of company IT policies are completely ignorant. That doesn’t change the sup position by P Phillips that the original account is the owner on an M1 i.e. Apple, silicon Mac and cannot be removed from admin status.

The Administrator account on Windows is entirely different than an admin capable account on a Mac. the equivalent type of account on a Mac (UNIX) is named root. That macOS account is not enabled on MOS, and it is completely crippled and what it is capable of doing a normal system.

You are unfortunately stuck dealing with a very large and ignorant body of thought, known as corporate IT.

You likely need to create a different standard account to use.

That might because the Original User Account ( User 1 ) is not only an Admin Account but also an Owner Account

Below link will provide additional insights about the Difference between Admin Accounts and Owner Accounts  

https://eclecticlight.co/2021/07/18/last-week-on-my-mac-the-perils-of-m1-ownership/

In addition to what P. Phillips said: it is a good idea to always have more than one admin account on any mac. Should a problem occur with your main account, a second admin account can be a life saver.

There isn’t any adde security running with a standard account. An admin account has no more power to do anything without authentication.

Welcome