Hi, im bearly new to playing the alto sax andi was wondering if you have to have a different embouchure for octave notes,. itll be a great help if you did

No. But, atleast, you shouldn`t, although just about everyone changes their embouchere when changing registers, unconsciously.
In a perfect world, you`re not supposed to change your embouchere, but you probably will change it, without knowing it.