Can’t find how to export in H264 codec
To enable H264 output in AE CC version: Go to menu: edit / preferences / output & enable checkbox: “Show depreciated formats in output module settings” Now you have the H264 output in your output settings!
To render in H264 format in AE CC2014 Send the composition directly to Adobe Media Encoder from After Effects (Composition > Add To Adobe Media Encoder Queue)