Legend of Zelda: Skyward Sword HD has been released for the Switch, and for those of you who haven't played it before, it's a different kettle of fish. Saving is very reminiscent of Majoras Mask for the Nintendo 64.
To save in Skyward Sword HD, you need to find yourself a Bird Statue. This is the only way you can manually save. Bird Statues are pretty hard to miss, as they are pretty tall, and certain parts of them glow a green light. The first one you see is directly opposite the Knight Academy.
All you need to do is interact with it by pressing A and then select the Save button. Choose the save slot you want to save to, and then select Save once again, and jobs done.
If you don't want to play anymore and want to save and come off it. Then select Save and Quit, then follow the instructions above, and after it's saved you will return to the intro screen of the game, and all progress will be saved.
There is an autosave in Skyward Sword in case your game crashes or you forgot to save. Autosaves are generally pretty good at saving, but it'll still only save at select intervals. It won't continuously autosave.