Newborn means staying at home… a lot. Forces me to think too.
Your home can be a place for classification. There’s colors and shapes, but that is to be assumed. How about temperature? Classifying objects, through touch, if they are hot or cold?
I’m walking around my home, but you could be out and about, like a department or grocery store.
Ask your child “See that over there. Do you think it is hot or cold?”
Choose items that are obviously hot or cold. Choosing room temperature water is not a good choice. Have the child guess, then attempt to touch to test their guess.
Safety is involved here too. Here is a prime example…
There are things that you obviously don’t want the child to touch because they are too hot or too cold. For those objects, you say “That’s hot, and it’s too hot for us to touch.”
Learning is good, but safety is paramount.