In the first language ,whichever that was,which came first ,nouns or verbs?

I believe verbs came first. Nouns could be indicated by pointing, and the concept of something like "tree" is really quite abstract when you include various types of tree within one word, so I think that level came later.

It is theorized that language first developed due to a need to organize group strategies for hunting. Strategies involve what should be done, more than they do what things should be used. And verbs nicely complement the sign language that probably already existed before the emergence of language as more than a series of grunts.

As for babies naming objects or people first, they do so because that is what we teach them, at least in our culture. We don't know that babies perceive a learned word as a noun. When they say "mama," they may be thinking of all the actions and feelings they associate with the person, like the Spanish verb "mamar," for example ("to suckle").

Interesting question! I'm going to say verbs are what makes language language, so that even though there may have been verbal (or gestural) signs for things (nouns), there was no language before there were verbs.

I did a post doc thesis on language development. As far as I was able to ascertain, babies certainly start with nouns, usually identifying Mama, Dada, siblings, pets, and moving onto other objects. However, much of the language they seem to understand best comes in the form of verbs that are given as instructions when they are small, for example, come, stop, eat, take, give etc. Unfortunately, one cannot actually ask the baby which comes first in their minds, so it's a lot of speculation!

The first sentence ever spoken was Let there be Light, which has both a noun and a verb.

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In almost all cases a baby's first recognisable word is 'No.'

Is that a noun or a verb?

This is just my guess, but I would say nouns. People assigned words to things they dealt with every day, so they could refer to them quickly and simply with a word. "Tree." "Hill." "Sun." If your definition of nouns includes verbal nouns like "running" or "swimming," then that's even better.

By observing babies, you can see that they name things (nouns) first and learn them first.