Here is a simple guide to adding the portal to your forum.
Your index page currently looks similar to this
scroll to the foot of the page and click admin cp
ACP > GENERAL > EXTRA SETTINGS
find the stargate portal info and click yes > press submit
now go to the STARGATE PORTAL tab
click enable block > submit
you will notice in the top right
Admin index • Portal • Forumclick on portal ........you should now see
in the site navigator box you can click on forum.......you should now see
If that worked you have successfully added the portal :smiley-cool:
You can now manage the blocks and how they display to suit your needs
ACP > STARGATE PORTAL > Blocks / manage blocks
Click on the green edit icon to make edits
It is advised you DO NOT delete these blocks, if you don't want them showing click on No where it say's block is active
If you want to change the welcome message to your own check out this guide
http://www.forummate.com/forums/phpbb3-manuals-guides/444401-how-change-welcome-message-portal.html