how to go to Hong Kong by train ?

Hello, I would like to make a train reservation from Xi'an to Hong Kong. When I do a basic search in your website it says that there is no train. But I found that there are some trains from Xi'an to Guangzhou. Then, I would like to know if there are any trains from Guangzhou to Hong Kong and if you could indicate them to me.

I am French and I would like to make these reservations online. Is it possible? If I give my hotel address in Xi'an, you can deliver the tickets to the hotel, right ?
Thanks and Regards,
Jeanne Verre