I have something to eat.改为一般疑问句

Have you anything to eat?

Do you have anything to eat?

若希望得到别人肯定的答复也可以说
Do you have something to eat?
具体看语境咯

Do you have anything to eat?

改一般疑问句要注意词语变换，第一人称要变第二人称，something要变anything，然后将do提前

Do you have anything to eat?
-Yes, I do. / No, I don't.

Do you have anything to eat?
这里something 要变 anything

Do you have anything to eat?
-Yes, I do. / No, I don't.