I made sure the audio button is checked, I have talked to tech support, and nothing seems to be working. It's a GoPro video with audio on it, along with an MP3 in it. I've tried using the Media Encoder to export it, I've tried using AVI, and neither works. I was able to get audio when I render it as a quicktime file, but the audio and video don't line up. Can anyone help me?
The audio and video should line up in a QuickTime file just like they would in an AVI. So, my guess is that something is awry in your render settings somewhere. If you're using AE CC 2015, there is a known issue with AVI files not having audio. known issues in After Effects CC 2015 (13.5) | After Effects region of interest
But your QuickTime should work. (And then you can use that QuickTime to make your deliverable in the Adobe Media Encoder.
So, let's try to figure out what's wrong with that.
When you say the audio and video don't line up, could you describe that more specifically? It sounds like you might be trying to play back a production codec and not a deliverable.
What codec did you use? Try Photo-JPEG. And then drop that resulting QuickTime into the AME and make an H.264. It should work.
There is a bug in the AE CC 2015 Bug Fix. It won't let you render audio along with video to AVI. Render to a lossless or near-lossles Quicktime codec, then use Adobe Media Encoder on the rendered file to get an AVI if you neeed AVI.