What about Pidgey? I missed a zillion times using tackle against Pidgey
That's just bad luck. Flying Pokemon are only immune to Ground attacks.
That said, Horn Attack also would have no penalty since it's normal.
When Peck attack was mentioned it was for the fact it is a Flying-type move, and the only one that Nidoran learns, and it is rather weak meaning it's not very good coverage for things that would be weak to it.
Good to know!
I'll go ahead and NOT learn that move lol
Also, should I not evolve Pikachu? He stays stronger if he doesn't evolve, right?
Last I knew there are few to no exceptions on pokemon that are better off evolved than not, and most of those apply to Mega-evolutions due to some almost completely changing a Pokemon's stats and available play-styles.
That said, I'm not an expert. I only vaguely remember things from friends who are far deeper into competitive pokemon than I.
If you're just playing the game to play the game, do as you wish as in most cases it's near impossible to make the game too hard to playthrough/enjoy.