So far I have exported a song to audio share in both wave and AAC. But I am stumped on how to upload my songs to different social media platforms. How do I go about doing this?
Each platform has its own instructions. You're better off checking on each of those sites for their upload instructions. The question doesn't really have anything to do with BM3.
Just googling with phrases like "how to upload music to Facebook" should get you started.
Audioshare can upload directly to Soundcloud. That's often how I do it.
Other platforms may require a more complicated process, but often you can upload files directly from the browser on iOS thanks to the FILES app giving you access to both Audioshare files, and/or the original WAVs created in the BM3 Export folders.