How Kadabra Evolve into Alakazam?
Kadabra (Japanese: ユンゲラー Yungerer) Is a Psychic-Type Pokémon Introduced in Generation I. It Evolves from Abra Starting at Level 16 and Evolves into Alakazam...
Kadabra (Japanese: ユンゲラー Yungerer) is a Psychic-type Pokémon introduced in Generation I. It evolves from Abra starting at level 16 and evolves into Alakazam when traded. From Generation IV onward, holding an Everstone will not prevent Kadabra from evolving when traded.
Can you evolve Kadabra into Alakazam without trading?
You can't, for the exact reasons you stated. While it would be possible if one of the ingame traders was willing to trade one, according to the Bulbapedia ingame trade list there is no such trader.
How do you evolve Alakazam?
Alakazam (Japanese: フーディン Foodin) is a Psychic-type Pokémon introduced in Generation I. It evolves from Kadabra when traded. It is the final form of Abra. Alakazam can Mega Evolve into Mega Alakazam using the Alakazite.