odyssey 2010

hey y’all, gotta check engine light and honda said the o2 sensors needed replacing. i read it’s better to just change all at the same time. wanted to buy them my self and have it installed but not sure how much o2 sensors the 2010 model comes with. i’m sure it’ll be cheaper than getting it done...

I have an 2010 Odyssey and it is not blowing air up front to its full capacity. The air it blows is cold, but even at full speed the fans are only blowing at what feels like the lowest possible air setting. Does anyone has a solution to this problem? PS: I know nothing about cars at all please...