Testing game problems (help)

Ok so I have a few questions. First, when I launch my project everything builds but then I get an unknown launch error. How do I figure out what the problem is or doors anyone know what could cause an error? I’ve done test projects before and never had a problem before.

Second, when I test my project as a stand alone game the lighting gets really bright and none of my audio plays. How would I fix that? And when running it as a stand alone game, does that show how it would look when packaged or not?

Update: not sure what I did right but there stand alone preview works and the lights changed brightness. Haven’t tried launch yet.