thanks for the help everyone. Dragontamer, I really appreciate your help, but I feel bad because I'm not exactly sure what everything means because this is my first project >_< and I'm learning this by myself. I'm having trouble learning how to calculate and especially measure things in a circuit.
However, I did try to make an amplifier after receiving responses from this thread. I had the parts to make the cmoy amp with a schematic and directions from tangentsoft. I tried to put it on a breadboard to see if I could connect it properly. There was audio when I connected the mp3 to the amp to my earbuds, but it was strange because the audio coming out from the was weaker than if I were to put my ear buds and listen directly from the mp3. I might have connected it improperly?
I also tried to amplify the signal by using darlington pairs. I had 4 transistors so I connected them together. I was able to light the LED with less volume now from my computer. But if I wanted it to work on a mp3, so I would need a lot more. So I still need to know how to make a circuit using an op amp for the audio.
As of right now, I'm still trying to figure out how to use an op amp. I understand the pinouts, but I don't really understand what each resistor is for when they are connected around the op amp. I don't know how to calculate or figure out where I would need a resistor and calculate what value I would need. What should I do? Is there any helpful resources I can use?