Verified answer

put it first in ur party if u dont have an experience share and than at the beginning of the battle switch it out for the pokemon u would use and than it evolves on level 20. i know from experience

i think you just have to level you magikarp up and it will evolve.

if you want to know what level it evolves then go to www.gamefaqs.com

you give to the guy that take cares of pokemon. it will level up there. then when it reaches the right level you can take out ur magicarp and evolve it.

didnt know anyone still played that game. haha. so yeah you have to get it leveled up or give it one of those stones you buy or find. some pokemon only evolve w/ a stone like that. idk havent played since like 4th grade.

good luck

Is there no other alternative?

level it up

Thank you for all the answers