SPOILERS!!!! DO NOT READ UNLESS YOU HAVE SEEN ENDGAME!!!
Answer:
It all really depends on the scene. The Avengers Compound makes me feel happy, until it is destroyed later on. Tony's house with Pepper has the mood of hope, like all isn't lost yet. Thor's house in New Asgard always puts a smile on everyone's face. I mean, it's hard not to laugh every time you see what a mess it is. Mostly everything else is pretty sad. It's dark, scary, and there is music in the background that makes people on the edge of their seats. The overall mood that the setting evokes is just sad. It even looks like all hope is lost outside.
Explanation:
I put that thing on the top as a precaution. I would never want to spoil an amazing movie for someone. It has been rereleased, so people should have already seen it, but it is still necessary to do that.