There are some questions the kuffar say like “if Allah is real can he make someone greater then He” or “Can Allah hurt himself” nauzubillah and I ignore them and I just tell myself the ayah “Allah can do all things” and then I leave it. Is this correct?

Yes, you do not need to engage with them. Allah is capable of all things, and what they ask about is impossible in itself, and the impossible is not a thing in the first place, as Shaykh Ibn Uthaymin said, so the question itself is invalid. It is like saying can Allah create something that is nothing, everything, and two things at the same time? what is this nonsense! This is not even a thing, and Allah is capable of all things.