This is my questions 1.How to catch Salamence?

1. Slamence evolves from a Shelgon, which evolves from a Bagon, which is in Meteor Falls. You can only find them in the room where you found TM02, if you have already. And, yes, it is past the Waterfall. But, once you explore the cave and find TM02, run around that room and you should eventually run into a Bagon.
2. I haven't really ever tried mystery gift, yet... So, I'm not really sure.

1) You need to get a Bagon, evolve to Shelgon, evolve to Salamence.
2) No you need a wireless conection

1. You can't catch a Salamance, you have to catch a Bagon and evolve it. Bagon it in Meteor Falls. But on the other hand if you have an AR or Gameshark, you can use the code Catch Trainer Pokemon and take a Salamance from a trainer who has one.
2. No you can't use a GBA Link Cable

1. A) You can always use cheats and then trade, but see b for the most efficent answer. ;)

B) Find Bagon in the room where you found tm02, then train it well and it will eventually evolve into a shelgon, then salamence.

2 A) No, you cannot use gba links. You need a wireless adapter.

B) Mystery events are for those of you that go out to the nintendo events.

The Pokemon people will then link you up and give certain rare Items that cannot normally be obtained.