There are several ways too earn TC, yes one of the easiest is to buy a booster and play alot as long its active, you can buy them here:
alternativley, you can also buy TC without playing, you can do that officially here:
but there are some players around who are willing to sell you their TC for real money aswell, IIRC for around 15.000 TC for 1$.
another way to make TC, which involves some work is by making art, textures for other people and sell them on the forums.
if you have some starting money you could start with marketing, buying items for a lower price and selling them for more.