Welcome to hell (errrr.. WGT). Now run away from this site as fast as you can... :) :)
As far as earning credits goes... you can earn 7 per day by watching the videos. Some of the offers are also good (I think.. have seen some complaints tho.. so be careful).
As for buying new equipment, I would suggest waiting until you get in the mid-30"s, level-wise, which is when the better lower level equipment starts to become available.
If/when you do buy equipment, try to buy the gear that will take you into the upper levels/tiers (you can get lots of good advice from the forums, friends, CC members, etc..
Again, welcome to WGT... best of luck.