Newborn size clothes

Karine 🌷 • Mom of two handsome boys.💙 English is not my native language! Please excuse any mistakes.✌🏻
Hi mommies, i'm a FTM and I want to know bout of much newborn size clothes I need to buy? And do pyjamas and onesies only are okay for newborn size? I don't think he will need cute outfit with jeans and all at this age..?