Gnus seems to start up OK, but I can’t find out how to subscribe to a group.
If you know the name of the group say U name.of.group RET in group buffer (use the tab-completion Luke). Otherwise hit ^ in group buffer, this brings you to the server buffer. Now place point (the cursor) over the server which carries the group you want, hit RET, move point to the group you want to subscribe to and say u to subscribe to it.