1) Tap on the lesson you wish to share
2) Tap the share icon in the toolbar (note: on smaller devices this may be hidden in the menu under the 3 dots on the far right)
3) Tap either "Email" or "PDF" in the menu that appears. The email option will allow you to enter emails to send the lesson to directly. The PDF option will download the PDF to your device - allowing you to open or share it as you wish.
4) If you choose to email it, enter the emails you wish to send it to