TL;DR Hinata was the first person to actually ACKNOWLEDGE Naruto. Iruka was the first one to TELL Naruto that he acknowledges him.

What episode does Naruto get recognized?

"Hero of the Hidden Leaf" (木ノ葉の英雄, Konoha no Eiyū) is episode 175 of the Naruto: Shippūden anime.

Was Sasuke the first to accept Naruto?

14 Sasuke Considered Naruto His First Friend

His brother was the closest thing to a friend he had, but he ruined that when he destroyed their lives. After that, Sasuke didn't bother with socializing. ... Though he wouldn't admit it, Naruto became the first person he cared for since losing his family; his first friend.