The first of all prophets was Aadam, not Nooh, may Allaah exalt their mention, since Allaah The Almighty spoke to him more than once. Indeed it is known that if Allaah The Almighty speaks with any man, that man is a prophet. Allaah The Almighty Says (what means): {He said, "O Adam, inform them of their names." And when he had informed them of their names, He said, "Did I not tell you that I know the unseen [aspects] of the heavens and the earth? And I know what you reveal and what you have concealed."} [Quran 2:33]

As for your second question, Nooh is the second father of humankind after Aadam and the first prophet after him too, because the flood exterminated all human beings except Nooh and those who were with him on the Ark. Ibn Hajar, the Shaaf‘i scholar confirmed this opinion, arguing that none had survived the flood with Nooh except the believers among those to whom he had been sent. Mankind was limited to those who remained with him whilst the others all perished. 

Moreover, the Quranic verse in which Allaah The Almighty Says (what means): {And We made his descendants those remaining [on the earth].} [Quran 37:77] apparently means that all existing humans are from the descendants of Nooh .

This suggests two possibilities: All those on board the ark were descendents of Nooh or some of them were not descendents of him but left no offspring.

Allaah Knows best.