@Eggtart: If you used the Voice Recorder app to produce the audio recording, then it won't be possible to segment the audio into separate files. The editing feature (pen symbol in the top right while playing the clip) allows you to trim selected areas of the recording, but this will delete the selected or dimmed area when you tap the scissor symbol, and can't be used to separate the audio.
Further to the above, your best bet in the instance is to use a third party sharing site/app to send the file to your friend. For future reference, if you tap the 3 dots in the top right of the Voice Recorder landing page, and tap on settings, then you can set the Recording quality to 'Low', which will significantly reduce the resulting file size.
