Q&A for How to Evolve Scyther

You can use the GTS to find and trade for one.

Go to the Pokémon's summary, and there should be a section that tells you what that Pokémon is holding. Also, you can tell if your Pokémon is holding an item if you go to your Pokemon's party, and there should be an icon next to the Pokémon's sprite.

(Partial spoilers ahead.) Yes, after you get to the Battle Tree on Poni Island after defeating either Red or Blue, you should start fighting in the Battle Tree. After a while, you should get enough Battle Points (BP) to be able to afford a Mega Stone. You get the Key Stone and Alakazite from Dexio after you beat the main story.

You should have one of your Pokémon use Theif on Magnemite. You could also find that out by having a Pokémon with the ability Frisk enter the battle.

If you mean "can you mega evolve Pokemon in fire red," you can't. You can only mega evolve in sixth-gen games.

Use thief.

No, it isn't, not until the 6th gen games.

Look up a guide on YouTube for this.

Yes.

He/she stole it from you. Use a trusted friend, such as your best friend, or if you have 2 systems and copies of the game.