have something to drink 拿些东西喝 have 拿的意思 变疑问句就成了
What do you have to drink?加上 be going to 打算 就成了
What are you going to have to drink.
(也可以说 have something to eat,have something to play)
drink something 喝些东西
What are you going to drink 和What are you going to have to drink 意思一样.