I'm searching to alternative to travel from Gold Coast to Sydney, other than flying.
Is there any train service from Gold Coast to Sydney? How long and which station to go? Is the train ticket able to be booked online?
There are no direct trains between the Gold Coast and Sydney. The line between Brisbane and the Gold Coast is Queensland Rail, 3 ft 6 in gauge. Between Brisbane and Sydney is standard gauge, run by New South Wales Trainlink (formerly Countrylink). They're not compatible, so you have to change.
One option is to take the early morning NSW Trainlink bus from somewhere like Surfers Paradise, which connects with a train at Casino (just over the NSW border), and then the train onwards to Sydney. Another option is to take an early morning Queensland Rail train from the Gold Coast up to Brisbane, then catch the Sydney train there.
Alternately, there's an overnight sleeper service. For that, you'd leave the Gold Coast on a bus mid afternoon, get to Casino late afternoon, then take the sleeper to Sydney arriving in the morning.
The timetables are available on the [NSW Trainlink site]( http://www.nswtrainlink.info/destinations/timetables), you want the 'North Coast Region' timetable.
The Seat 61 page gives a lot of info on what the trains are like, what the sleeper compartment is like etc.
Ticket prices vary depending on how far in advance you book them, from about $90 to $130. Alternately, buy an East Coast Discovery Pass which is currently $130. That allows you to stop off as much as you want, as long as you keep going in the same direction. That would allow you to take a few stopovers on your way down, to visit some more of the nice places along the coast. If you're thinking of that, see this question on where to stop off on that journey which may help!
Sure, I've done this very trip.
Trains can be booked online, and take about 14 hours overnight. The tickets vary if you're a student or have a travel pass, but a regular ticket in Economy can be $87.
Warning: even in April it got very cold in the middle of the night on the train. Bring extra layers!
This is possible. There is a daily daytime and as well as a night train from Brisbane to Sydney. Tickets can be booked online. However, sleepers cannot directly be booked online. You can book by phone or go through an agency.
The Man in Seat 61 has more useful information regarding this topic, including schedules, prices and booking options.