Magikarp is a Pokmon that is notoriously difficult to train. It has a very low base stat total, and its only attack, Splash, does no damage. However, Magikarp can evolve into the powerful Gyarados, which makes it worth the effort to train. There are two ways to evolve Magikarp: by leveling it up to level 20, or by using a Water Stone.
Leveling up Magikarp to level 20 is the more traditional way to evolve it. This can be done by battling other Pokmon, or by using Rare Candies. However, this method can be time-consuming, especially if you don’t have a lot of time to play Pokmon Go. Using a Water Stone is a much faster way to evolve Magikarp, but Water Stones are rare items. They can be found at PokStops, or they can be purchased from the in-game shop.