My game is too dark...

how do i turn up the brightness on my game, its not the computer and im very lost someone please help me.

If you go to Edit>Render settings, then change the ambient light to be a brighter color, it should light everything up.

Have you tried creating a light?

Definitely the solutions are what tanoshimi and KingMatthew said.
In case you have a light and you want more brightness, increase the intensity.

Although I am sure that is not the problem, for future work, take into account if the fog is activated.