They really shouldn't have worried about establishing the world for the entire first season. I'd introduce the 2ndary characters in the very first 2 episodes, then build on them and that later ones. But most importantly I'd make sure that the main characters are worth watching to begin with.
I did like the art style in this though, it was pretty good. But I must confess that initially I thought this series was taking bits from the webcomic Bottropolis.
The idea of a world with nothing but robots is an old but interesting one, but its a waste when you turn around and stick them into a high school since we already have enough sitcoms about high schools. If anything this series concept reminds me of Aaahh!! Real Monsters (though that show did school stuff well, because it wasn't just in a school).