As a Tutorial step, sure why not. You learn the spell, the character panel switches to spellbook view, the newly learned spell is highlighted and a tooltip pointing to it tells you that you can now Prepare it if you are willing to use it.
But only once, and only if Tutorial is enabled in the settings.
Yes exactly, and then you could also find it in the "tutorial" chapter of the menu.
I have done like, three or four playthroughs of this game, maybe five and I have never been able to figure out how to actually prepare spells.
I am not sure either: you can switch outside combats through the spell book but I am not sure if you also need to rest, like in the previous Baldur's Gate games?
