Clearing the first battle (Chapter 1 "Battle of Hyrule Field") enables you to save your game.
* Please note that you are unable to save during a battle.
Once you become able to save your game, you are able to save at the following timings:
Manual Save:
- Press [-] button on the Hyrule map screen to open Systems screen.
- Select [Save].
Auto Save:
Auto-save is performed at the following timings.
- When a battle stars
- When a battle ends
- When a option is changed