ASL asks questions with the face first and the hands second. A WH-question (what, where, when, who, why, how, which) gets lowered eyebrows and a slight forward tilt of the head. A yes-or-no question gets raised eyebrows. The hands make the same signs either way; the eyebrows tell the listener what kind of answer you want. Beginners who skip the eyebrows get confused looks, because without them a question reads as a statement.
The second thing to know: the question word usually comes at the end of the sentence. English says "Where is the bathroom?" ASL says BATHROOM WHERE, with the eyebrows down on WHERE and held there until the other person answers.
The six WH-signs
What is open hands with a small shake, or an index finger sliding across the other palm. Where is an index finger wagging side to side. When circles an index finger around the other index finger and lands on it. Who is a bent index finger at the chin. Why touches the forehead and pulls down into a Y. How rolls two bent hands open.
Learn all six as a set, each with lowered eyebrows. Say the English word under your breath while you sign it to lock in the pairing.
Which and how many
Which alternates two thumbs up and down, like weighing options. How Many? starts as closed fists and springs the fingers open, with a questioning face.
Questions you will actually ask
What's Your Name? is YOU NAME WHAT. Where Are You From? is YOU FROM WHERE. How Old Are You? is YOU OLD HOW-MANY, signed from the chin. Notice that every one of them puts the question word last.
What Are You Doing? is DO-DO with a questioning face. What Happened? is HAPPEN WHAT. What's That? points and asks. Where Are You? is YOU WHERE, and it is how you text a friend at a crowded event.
Yes-or-no questions
Any statement becomes a yes-or-no question with raised eyebrows. You Deaf with raised eyebrows means "Are you Deaf?" You Hungry with raised eyebrows means "Are you hungry?" There is no DO or ARE sign to add. The face is the grammar.
Answering
Short answers are fine and normal. Yes, No, Don't Know, Maybe, Not Yet. A nod or head shake while you repeat the key sign is also a complete answer: HUNGRY with a nod means "yes, I'm hungry."
Practice
Ask yourself five questions a day in the mirror, with the eyebrows. YOU NAME WHAT. YOU FROM WHERE. YOU OLD HOW-MANY. TODAY WHAT-DAY. BATHROOM WHERE. Then answer each one. Within a week the eyebrows will come on their own.
Next: learn the pronouns that go inside these questions, then read why facial expressions are grammar.