Baking map texture from blender vertex paint

I'm a newbie in blender 2.8 and made a model for a low poly map. Then colored the map with the vertex paint mode so the coloring fits the polygons of the model. I need to import that model and its texture to unity, and for that I followed a lot of tutorials. I finally found the following method:

1. Shading tab: created new image to bake to (2048 x 2048 res) all other settings left on default
2. Shading tab: created node for the image
3. Shading tab: created node for vertex color
4. Linked vertex color node output to main (principled BSDF) node "base color" input [Now model in object mode appears with my vertex painting]
5. Now in Render: using "cycles" rendering engine, "bake type": combined, all settings in default

Here's where I hit some troubles,

1. The baked texture turns out really dark
2. FBX model imports just fine but when importing the texture to unity and assign it to the mesh, aside from importing with the darken colors, it appears out of place and distorted.

I'm probably doing something wrong but I can't put my finger on it

Object mode and the shading nodes I have set up:

Baking result, as you can see, the result image has really darken colors:


Back in unity, model and texture are imported correctly. But when attaching texture to mesh, texture aligns incorrectly:

 

Have you created the UVs for your mesh?