Q is a defensive character straight up. If someone turtles back at you, you just taunt, and once you’ve got 3 of those in, you have the defense of 2 characters. His big areas for damage are command throw, hit confirm close mk into super, and kara throws. Command throw is kind of slow, and against stronger players, they wont get captured by it much, so you have to great creative with making your opponent block when you want to command throw (simple set up is jump in fierce, land, command throw).
Otherwise, he requires patience. You don’t have great tools to get in against your opponent, and the tendency for a lot of Q’s is random dash punches, which can work against some mid tier players, but it can blow up in your face if its counterpoked or parried. Thankfully because of the taunts they usually come to you, so you’ll need to get really good at blocking and teching.