WGT offers many ways of getting free credits.
The most efficient way for someone of your caliber is going to be to participate by completing offers and filling out surveys. Check out the "GET CREDITS > EARN FREE CREDITS" tab at the top of the forums here. You should be able to get hundreds of credits in just a few days.
But I'm going to be honest with you. Until you buy some new clubs, you probably won't be able to compete very well in your tier tournaments. Some people buy new clubs on the first day they're hear, which immediately gives them an advantage over other members, who are trying to climb the ladder from scratch.
Give the game some time, take every free route possible to earning credits, practice practice practice, and have a great time... That's the best advice I can give you.