How do you get to the resort area,fight area,and survival area?

Get the national dex and explore the little island with the battle tower in it oh and make sure to pick up the super rod from the fisherman around the the boat area

You must get the national Pokedex from Profeesor Oak after Finding all the Pokemon in the sinnoh Region and after beating the Elite Four and the champion. Your rival gives you a ticket to go to the fight area, but you must get the National Pokedex to get to the resort and survial areas.

You take the boat that is in the snowpoint city. The guy by the boat takes you there.

To get to the first area you need to have completed the Pokemon league. To get to the other 2 you need to have the national dex. To get that you need to complete the sinho dex.

p.s. If you see a fisherman on the right when you are going to the survial area talk to him he will give you a super rod.

First of all you need to have beaten the Pokemon league. Once you have done that and you are transported back into your house in Twinleaf town, your mum will have a message for you. She will tell you that the message is from your rival and they want you to head to Snowpoint city and take a boat. The boat from Snowpoint city will take you straight to the Fight Area!
The survival area and the resort area are next to the fight area, but you will find people blocking the path to get to them. To access these areas you will need to have seen all 150 Pokemon in the sinnoh pokedax (excluding manaphy) (Hint- to register Palkia, just talk to the old lady in her house in Celestic town). Once you have seen all 150, head to sandgem town to Professor Rowan's lab to meet Professor Oak, who will give you the National Pokedex!
With the National Pokedex you will be able to enter the Survival and Resort areas, not to mention a few other previously inaccessable areas in the game.
Hope I helped.