Watch the 3 lotr movies and/or read the lotr books first. Silmarillion is much more into the world/universe building. It helps to have some very developed characters, even a thousand years later, as a grounding to the family trees and new characters of Silmarillion.

I would, yes.

I wouldn't necessarily discourage it, but it might be a tough read. Many people read and consume the silmarillion because they are motivated to continue living inside middle earth after finishing the Lord of the Rings and absolutely loving it. If you don't have that motivation, you may have difficulty maintaining interest in reading these ancient myths of a world that you don't have a connection to