1) do you mean you want to go to Hong Kong or Guangdong? then it would be 「我想去香港/ 廣東。」
2) 住酒店幾錢一晚?
3) do you want to ask the way? then you can say 「唔該我想問...係邊? 點樣去?」
4) the literal translation of "how far" is 「幾遠」, if you want to ask the distance from one place to another if you walk on foot, then you can say 「遠唔遠架?大概要行幾耐到? 」(is it far away? it takes how much time to walk there? )
5) 「可唔可以再平D?」or just 「平D(啲)啦 !」
but sorry i don't know the answer to your last question...maybe you can search it on the internet
you can survive in HK even if you don't know Cantonese, English would be enough for survival lol