Passwords and ID issues

[TedP]

I haven't used my Mac min for a couple of years but have now decided to get back into it .
I have successfully updated my Apple ID and password.
When I switch on the MM it opens to a login screen with my user name and asking for a password. I enter the password I set up with my apple ID but that is rejected.
If I don't enter a password at the login screen and simply press the Enter key the MM then opens to the desktop OK.
I then tried to update the OS only to find the whislt the High Sierra update seemed to have been download and installed it actually didn't. When I check on system updates I'm asked to enter the password. I tried the one I set up for the Apple ID but that is not accepted . I then tried to create a new administrator but could not do that because again I need a password.
I'm really as a loss re what to do next . Any help and guidance would really be appreciated

 

[Lufbrarunner]

The apple ID password is not the one you need to log into your mac mini.

 

[TedP]

The apple ID password is not the one you need to log into your mac mini.

Thanks . I've solved the problem. I manged to find the original notes I created when I first purchased and set up the Mac Mini in 2014