You may have noticed that there's no save button in the Weebly editor, and there's a very good reason why. That's because everything is saved for you automatically while you work, so you don't need to publish or do anything special to save. When you're ready to take a break from working on your site, you can just close the editor - you'll be able to pick up right where you left off when you're ready to come back.
What about blog posts? If you guessed that you do have to save a post if you need to come back to it later, you're exactly right.