The title can also be translated as "Beauty of Evening" but in the archaic sense "ilu" also means "fun", "joy" and "partying".
The same is with the word "päev". In modern and common speech, it means "day" but in folk songs, it is often used for the sun. But sun (päike) is actually diminutive of "day", so it makes sense. (Also, the first comment here might be useful: https://lyricstranslate.com/en/tuleloits-fire-spell.html )
However, I don't know what archaic meanings for "kuma" and "mõnu" are, so I translated them according to their modern meanings. Also, in the original folk song lyrics, there seems to be "kuulduma" instead of "kuuluma" (belong), so the lines in question become "X can be heard in Y land" (Jennifer Runner's translation in Youtube's comment section understands it the same way; she translated "mõnu" as "pleasure").
Instead of "perch" (aka "ors" = dialect for "õrs"), they might actually be talking about something also called "kuhjavarras" which is some kind of vertical bar around which a haystack is formed. "Nõtkuma" means "to bend up-and-down (under weight/pressure)" like the device called spring; or "to move quickly back and forth" (when it comes to trees, I think). So, it is a kind of shaky movement.

According to a forum thread I found, the lyrics (and song) are a modified version of folk lyrics from Kuusalu parish http://meestelaul.metsatoll.ee/foorum/read.php?9,4293
and from "mina laulan, lauda notkub" a different song or tradition begins. It seems to have been put together of three "songs".