Hi, I'm not a teenager (far from it ha ha) but this could be an opportunity to maybe convince WGT to set up a forum category for under 18 players with an intro and description of types of activities that under 18's can participate in.
If not (although I can't imagine WGT totally ignoring young gamers as a large future group of paying customers) you can start your own thread in e.g. Community Introductions and give it a catchy name like "Under 18 members click here!" or something, you may even convince one of the moderators to make it "stick" so that it remains near the top of the threads.
An example activity to get around the no tourney rules for under 18's was suggested by DAZZA501 (pasted below from another thread which you might find interesting reading). Others may have other ideas.
Keep it up with your good questions and suggestions on the forum. Good luck!
-Keith
DAZZA501:
What you can do is put a post in your club forum that you're starting a tournament and ask for sign ups.
Then you set the course to be played by a certain time or day. Members pair up and play their rounds together (for confirmation purposes). After they're done they can come back to the forum and tell you their score or post a screen shot of their card from the game they played.
When all the scores are in you sort out the leaderboard and you have a winner.
If you so wish you could ask players to put in prizes to a kitty. Sort of sponsoring the tournament.