I'm a beginner in blender and am trying to model an axe for a logo, but when scaling the "sharp" edges, they scaled outward from the geometry origin, which made some edges go inward, instead of facing outward (showed in example foto). Is there any way to reference an outer edge loop to make the inner edge loop scale outwards from that edge, instead of from the geometry origin (if that makes sense)?
If I'm understanding you correctly... You want to create a sharp edge to your axe. The way I would achieve this is by using the Offset Edges which is now part of the Edit Mesh Tools addon.
First in object mode apply the scale (ctrl-a -> Scale) (I removed half the axe for clarity)
In edit mode remove the faces around the perimeter of your axe, select both faces and do Edge -> Bridge Edge Loops
Next add an edge loop to the centre of the new faces. ctrl-r -> hover over the faces -> left click -> right click (drop the loop in the middle)
Then choose Edge -> Offset Edges -> Move and play around with the settings
You have a LOT of verices around the edge of your axe, so you will get some edges crossing over each other if you pull out the edges too far, but this is a whole other issue :)