gpg help

[Dan Track]

Hi

I'd like to edit the gpg.conf file in my home directory, I'd like to
set the "default key" to a particular key I have. However I don't know
what info I'm meant to input into the "default key" fiedl. Currently
there is a id in there written: 621CC013. I don't know what this is
and how to find a similar type of id for my keys. Could someone please
help me with this.

Many Thanks
Dan