Right, i’m new to unity and really need some help! I am trying to make an object move left and right automatically from when my game starts…i don’t even know where to start to do this!! any help would be great!!
Thanks 
First, the usual recommendation: Work through some of the tutorials and reference materials before diving into your first game. That way, when you do tackle your first project, these things won’t seem quite so mysterious 
As for your question, as with most things, there are many ways it can be done. Also, it depends on how the object is set up. Does the object have a rigid body or character controller associated with it?