What will/would you have in/for dinner?
What shall i make for/in dinner?
What would/will you like to have for dinner?
What you had for/in snacks?
What you had for/in breakfast?
What will you have for dinner? Correct.
What shall I make for dinner? Correct
What would you like to have for dinner? Correct
What you had for snacks? See below
What you had for breakfast? See below
1, 2 and 3 are correct.
4 - I'm not sure what you mean. Are you asking what the person had available to eat as a snack, or are you asking them what they ate as a snack?
Either way, "What did you have for snacks?" would work.
5 - What did you have for breakfast?
Remember that "had" when used in the interrogative becomes "did I/you/he/we/you/they have". You need the auxiliary "did".