Who is the wisest Greek and wisest Trojan? Who is the most foolish Greek and Trojan? Which character learns the most in the poem? Which character learns the most?

Nestor was the wisest Greek

http://www.iliadtranslation.com/characters.html

Odysseus- son of Laertes, ruler of Ithaca. Wisest of the Trojans, an eloquent speaker, and was sought for his counsel.

I think Achilles the most foolish because he believed himself invincible.

Hephaestos the most foolish (as in behavior)