I'm getting back into these games. When I was a kid, I would play the "dumb way" by just using my starter for every battle and creaming everyone. But I want to play the "right way", i.e. raise a team of Pokemon

But I don't understand how you're supposed to do this without insane amounts of grinding. Is grinding required? Or if you just use the Pokemon that is the right type for the situation, will they generally be at a good level throughout the game?