Mr Bojangles

Hello, I am a undergraduate student studying economics in the hopes of one day pursuing a PHD. I have downloaded STATA and am faced with the task of self study. Would anyone have tips or advice on how to go about learning this software package in a way that is geared towards economics. I figure any RA position would want you to prove your proficiency with the software. I just wonder how you would show that. At my university, I have found some previous class assignments from an econometrics class that require the use of STATA. I am thinking it may be a good idea to mess around with those assignments and see what I can do with them. Maybe I could even use the assignments as a badge of proof, a way to show proficiency in STATA. If anyone has advice for me, I would be happy to hear it. Thank you.