No worries, I’m still learning myself. Check out the ArchiViz section of the forum, especially “Koola”'s thread.
Yeah Screen Percentage (“SSAA”) makes things slower but is worth it and can still be realtime with a fast graphics card. 
I’ve only just found out about “Blendables”, that’s for things like:
https://www.unrealengine.com/content/a7386fac224a4e629040f993a9c84333
Also for Post FX there’s interesting assets such as:
https://www.unrealengine.com/content/a75a2fba3f2b41d1b9302c4387e86c22
https://www.unrealengine.com/content/e6410a83d0704a2d9c0bf800628dd816
OK that’s all for now.