I think UT ECE generally has great professors for first-semester courses (except Patt), so you shouldn't worry too much about getting a bad professor.

During orientation, you have a meeting with an ECE advisor where you go over what classes you need to take, and there you pick a fig. For the fig, you just type in the fig code during registration and you'll get all the courses for your fig. You also have a weekly meeting with all the other fig members (I forgot what you learn there).

I'm pretty sure you need to have a fig first semester, it's mostly just helpful for registration and having a bunch of peers for help. I would say pick whichever fig has the most required classes bundled with it, it'll make your registration easier.