In v0 there's no manual save, just autosave. The only manual save is at the end of the version.
In the next version I changed that because autosave was fucking with some events. So v0.1 will have no autosave, but will open the save menu for manual save at the start of every new chapter. Each chapter will have around 10 to 20 minutes, can go up or down as your reading speed.
This way I can "simulate" some of the freedom of the Renpy, for ppl saving in various slots, so they can go back and make different choices wherever they want.
The save is located inside game folder, inside "www", and then the folder "save".