how long must i wait?

I am an American citizen who has been living in Russia for the last 2 years. I am now 16 and 7 months and I need to learn to drive. I moved to Austin Texas this summer and I hear there are laws about the length of time you must keep your permit before getting a liscense, and a longer length of time before being able to take my sister to soccer practice, since she is also a minor. Please help.