Can I get all of the endings in one playthrough?

[Farkus]

Or do I need to do one play through for each ending? And if not, can I lock myself out of any of them?

[Draculol]

you may get all endings/achievements in a single playthrough, + i don't think it's even possible to get locked out of anything, you'll definitely miss some stuff along the way and you're always able to return to previous areas.
when you get to an ending you stay in your current playthrough as there is no ng+

feel free to explore and experiment.

[Aava]

You can lock yourself out of ending A if you collect all the spells + a secret, basically impossible to do without actively attempting to. As the other person said you continue playing your save after every ending. Its not a full reload though like Zelda BoTW/ToTK, the world enters like a "post-game" with some new dialogue.

[Farkus]

Ok, sounds good. Thanks guys!