As a new player how do I get event items like Eternal Flame? Are they random from like glory chests too?
No, you cant obtain them in chests. Besides one weapon which you obtain via a questline (dont want to spoiler here which and where 
) event weapons can be obtained for glory in the reward tab.
Every week a new troop or weapon gets released which you can buy in that week for glory. In the past, those event weapons have returned to be bought for glory again but often a little higher cost. With the change to 1.0.8 those repeats have currently stopped.
So to obtain eternal flame right now, you
a) have to wait until they start reselling old event weapons (likely when 1.0.9 comes around i hope)
b) get it for $ when its offered in the sales bundles.
There is sadly no other way right now.
A little off topic, but Sheggras heart can be obtained by 40 in each mastery brown/red? Right?
Brown/blue.
Roger that! Hmm… u sure btw?
Sheggra’s Heart is definitely brown/blue for its mana cost. As for the masteries to acquire it, red/ brown makes sense, but I’m not sure.
Roger that!
The masteries are the same colours as the mana cost.
thanks! Ok, then we have it.
http://gemsofwar.com/game-guide-weapon-list/
gives the requirements too. its at the top of the page next to troop list and world map. 
Thank you, @Aelthwyn!