newborn clothes

This may be a silly question but I'm a FTM and have no idea. Anyway, I only have a handful of newborn outfits for baby, mostly just plain onesies and a couple pairs of pants. Do newborns need newborn size clothes or can they immediately just go into 0-3mo? Obviously if she can't fit into newborn we'll skip it but is it okay for her clothes to fit a little bigger and grow into them? Like I said, may be a silly question but I appreciate any answers!