There is no other garment necessary for clothing your child than a sleeper or footie. One piece does it all.
Make sure it’s got a zipper and doesn’t have 28 snaps which can only be assembled in a particular order. As the kid is screaming. At four in the morning.
Your wife may insist, especially when “going out”, on dressing your child in “cuter” clothes. A shirt. Pants. Socks. Perhaps a hat and gloves, and a jacket.
All I know is when I’m the clock to take care of the boy, his attire consists of one item, and one item only.