"Hace muy frío hoy." It is very cold today. I don´t think you would use the progressive for this statement.
Hoy Hace mucho frio.
¿Qué estás haciendo hoy? is the best way to ask "What are you doing today?" in Spanish.
"I hope today will be a fun/enjoyable day for you. (assuming you meant un dia, not undia.)
Hubo mucho frio. The correct answer for the preterite (past) tense of being cold is different than the present tense. The present tense, Hace mucho frio has a different form of haber.
¿Qué hace / hacen / haces / hacéis?This has another meaning different from "what are you doing": que te haces
¿Cómo estas hoy? (Informal) ¿Cómo esta usted hoy? (formal)
"How good/great. What are you doing today?"
"Quién no está aquí hoy?" means "Who is not here today?"
Translation: I'm fine like this. What are you doing today?
this is my picture for today
Like this job today.
It means: Who's playing today?