It can´t be said "Hice algo hoy", I studied in the university and we were always told this past time it´s not used with "today" - it would be "he hecho algo hoy"
"Hice algo hoy?" is "Did I do something today?". This question is asking whether "you" did something today.
But it doesn't matter which person. It would also be "Tú has hecho algo hoy?" because you have too use préterito perfecto with the signal word today
it's called the present perfect
My Spanish verb book lists "hacia" (with "a" accented) as the form for both the first person AND the third person singular. Since "you" can be either "tu" or "usted", why would Duo mark me wrong for using "hacia"? I don't get it.