If you don't have The Silmarillion you might consider obtaining it. It starts with the primeval world of creation and progresses through the Noldorin rebellion, the First Age, Numenor and on to the Third Age.
There are a number of progressive formative volumes such as the two volumes The Lost Tales; also the whole The History of Middle-earth series. A veritable mountain of developing Middle Earth reality.
If you don’t have The Silmarillion you might consider obtaining it.
(-)___(-) Ive read it front > back a least twice but its been awhile... Lost Tales and others as well