I've made good experiences with Udemi, so far. I can recommend "Realistic Lighting for Games" by Wilmer Lin and "Complete C# Unity Developer 3D: Learn to Code Making" by Ben Tristem and Rick Davidsohn. The courses are often on sale, I've never paid more than 12 $ for each, a bargain!
Screenshot from the code making course (my level design and lights, code from Ben Tristem):
