Hi, you can say: 我想吃[dish name]。meaning 'I would like to eat...' 我要[dish/drink name]。literally means 'I want'.

Maybe the most useful thing is to figure it out with your finger and say 我想点这个（点 means order here）or 给我来一份XXX or 我想要XXX It's all OK. If you want to ask questions like what is special here. You could say 有什么推荐菜吗？

uU can say:hey，man.u know l love Chinese food very much .could u recommend some nice food for me？ ILol,just a joke .But it works .u can try it next time ...

For fast food, use fingers to point and say 这个这个这个这个. I don't like talk much in those restaurants. In other formal restaurants (for formal I mean a menu sheet and a waiter), say 你好，我想要 at the beginning, and you are good to go your finger games(这个这个这个这个....), and 谢谢 by the end. LOL. Trust me, it makes you like a real Chinese!

Hi, mate. I'm Fred Arrize, from Brazil, I've been studying English for ten years and I've been teaching for eight months. I'm looking foward to meeting a partner to talk to and exchange language experience. I use Skype, WhatsApp and Facebook for learning purposes. Please get in touch. My skype name is fabiopensa1