Sudo port Password login

[Hans Fredrik Johansson]

Hi,
I have just installed Macports on my Macbook MacOS High Sierra 10.13.6:
First I installed Xcode 10.1
then I installed Commande line tools
then I installed Macport for MacOS High Sierra 10.13.6:

when I type : « port version » in my Terminal I get the answer :
	Version: 2.6.2

But when I type « sudo port selfupdate » they ask for my password:
	Password:

I tried my login password (for fjhome account) and got the answer:
	fjhome is not in the sudoers file.  This incident will be reported.

If I try the password for the admin I get :
Sorry, try again.

if I log my self as « su - admin » and tape again « port version »  I get:
-bash: port: command not found

So my question is what is the password they are asking for?
Why do they ask for a password?
And why does it not work?

Could anyone Please help me.
Best Regards,
Fredrik