Unable to erase and start again on Mac mini due to unknown admin password

I set up a work profile which led to me having to login with that profile, which pushed a new admin password - which I don't know what it is (having tried the various passwords used in my set up).

I can't erase and start again as every way to do this asks for an admin password - I can only login on one standard profile.

[Re-Titled by Moderator]

Original Title: I don't know my admin password, so I can't even erase and start again on my new Mac mini. help