You can broadcast live only if you have access to internet. If you don't, you can still record an episode and then publish it as a regular episode once you're connected.
There is no way to schedule a live episode. In regards to the link, the episode page is created the exact time you go live, so it is not possible to have it in advance. You can share your live episode by visiting Spreaker Studio for desktop or mobile, while live, and clicking on the share button to get the URL to the episode.