After the events of the battle Naruto training his Pokemon and stopped a few times to make his Pidget and Rattata slot stronger and it did.
He captured two Pokemon as well a Weedle and a Carterpie.
Flashback...
The 2nd day of training ...
In the dark and dense forest were trees are abound Naruto was up and he sees A Carterpie looking and rummage through his supplies...
"Hey little guy what you doing ? " Naruto asked with a smile.
The Carterpie smiled and nudged Naruto hand.
" Say you want to come with my journey you could come and meet new people and grow stronger " Naruto smiled.
with that both of them gotten stronger with their trainer as they battled some more wild Pokemon and even some trainers.
Weedle evolved into it final form a Beedrill and his Carterpie evolved all the way up to Butterfree
Now he made it to the next city and he will rest and place some Pokemon back inside the Pokemon lab with professor Oak...
Next day...
Pewter City ...
Naruto has three Pokemon with him and now he is ready to challenge the gym...
Naruto walks inside the gym and he has to battle a Pokemon gym trainer...
he whips out his Pokedex and he sees a a new Pokemon...
"Sandshrew is a ground type Pokemon and is called the mouse Pokemon. It can burrow underground when its scared but when trained by skilled trainers can make it stronger " the Pokedex said.
"I see , Charmander get ready for battle " he said getting ready to challenge his opponents Sandshrew.
"Shanshrew use scratch " the camper trainer said.
"Charmander dodge and use ember " Naruto said as Charmander ember hit Shandshrew and it did some damage.
Shandshrew then got up "Use rock tomb " Shandshrew used rock tomb and it hit Charmander .
Charmander was weakened and was slowed down by the move
"Now use scratch " naruto ordered as Charmander did as ordered and knockout Shandshrew.
"alright geodude come on out " the camper trainer said as the rock/ ground Pokemon appeared.
Ash Pokedex appeared and it said " the rock Pokemon if you step on it as it will bet angry because people mistake it for rocks." It said.
"I see Charmander are you ready ! Then use Ember " Naruto said as ordered it and Geodude took some damage.
"Alright now rock tomb " the camper trainer ordered as Charmander took it and fainted.
"Charmander you did a good job now rest." Naruto said.
"Alright Bellsprout I chose you " Naruto said as he pulled out a grass and poison type.
"Bellsprout use vine whip " Naruto said as his Bellsprout took out a vine it had and whipped at Geodude and it was fast enough that the rock type went flying.
He was defeated ...
Naruto went out to heal his Pokemon at the Pokemon center.