No such thing as a Trial version for the Official LW. LW Basic is the Free version. LW Pro is a paid version. If LW Basic does not connect for you then LW Pro will probably not connect either.
http://www.gnutellaforums.com/connec...t-connect.html
As far as activating LW Pro, you will find the activation code on your personal LW Pro download page.
* EDIT: It appears LW does from time to time offer trials of LW Pro able to run as Pro over a short period of time.