Woopa

I tried to find the xp share but I couldn't find it, I went to the one close to vermillion city but it only gave me a Item Finder

So I did kinda a related post to this but I tried changing the ability of a pokemon, but a person suggested that you need to check the pokedex but I did not really get how so hopefully you could help me.

But How do I know if a Pokemon can change their ability in pokedex

Oh wait I just realized

Hi, thank you btw but when I give it to Zorua It says it has no use, should I give it to him on a battle on a specific place or zorua can't change?

So I just got zorua and I really dont like the ability Illusion and hoping to change it but Im not sure if you can change it so if you know how please tell me!