Why cant i connect to wifi on a new macair

Why cant i connect to wifi on new macbook air? I have read there are problems and that i should update software but cant do this as i dont have wifi!! am typing this on ipad. Tried to use iphone hotspot but this wants wpa2 password, wont accept what i think it should be. How can this not have been addressed from what i have just read this has been happening for sometime. I am on the road and am trying to connect to public wifi so resetting routers is not possible. Help!!!