Best hotel near main train station in Hong Kong

My husband & I will be visiting our daughter who is living in GZ for a year. We would like to take a side trip to HK just for one day. Question 1) What train can we take from GZ to HK, early in the morning of May 15? My husband & I will stay the night, and our daughter will return to GZ. Question 2) I'd like to know whether the train from GZ goes to the HK side or the Kowloon side, and a recommendation on a hotel for that one night. My husband & I will then go to the airport the next day to return to the US. Thanks!