Audacity

I am new to this whole process. I am slightly familiar with using I-Movie and Garage Band sound effects. I have never used Audacity before. I did not have any trouble recording what I wanted, however I could not find any sample or template sounds on the program. There were three immediate options for sound: white noise, silence, or tone. So, I inserted the white noise effect at the beginning and end of my clip; just to show that I knew how to insert sounds into my clip. There was also another issue of exporting my file as an MP3. I had to use the Macs in one of the labs on campus and for some reason, it would not let be do this. I tried to open it as a lame file instead, if that makes sense. This did not work, so I am feeling rather frustrated!