"tired" is an adjective, it tells us something about how the person feels. So you use "be" (are, is, am)
Or for example:
Is the skirt yellow?
"yellow" is an adjective, too. We learn something about the colour of the skirt.
"do" in questions refers to an action. And it is an auxiliary verb . You use do/does to make questions and negative sentences.
Do you have a bike?
Do you speak English?
Do you think she's good at maths?
Does he like cats?
They don't work.
She doesn't drive.
"do" can also be the main verb.
What do you do?
They don't do anything to help their mum.
Hope that helps