Hi Reira, welcome to Rescreatu! We're glad to have you! :)
The stock market is probably the easiest way to make tu, if you have a little patience. The key is to buy low (under 30 TU) and sell high (above 300 TU). You can buy or sell a maximum of 50,000 stocks a day, so once you have a good portfolio built up and you can afford it, you should take advantage of this limit every single day. My favorite stocks to buy are ARM, BLA, BOO, FRE, and TOY.
If you need help with anything else, I'm here for you! Feel free to Rmail me. I will also be subscribing to this thread, so I'll be around.
I hope you're enjoying yourself so far!