My lights on my Unity do not work! The only way they do is if I put the intensity all the way, and then my game looks completely fake. Any ideas? Thanks in advance! 
In open ambients I usually put a point light high above the terrain (600 a 800m) to simulate the sun, and adjust Range and Intensity to get the desired results. You can also use a directional light, but it’s harder than the point light. Anyway, a little ambient light is useful to reduce the contrast.