Help newbie here

So I played this for 3weeks and im on floor 126 lvl 89 warrior
I’m just wondering how do I get max luck?
how do I get so many stones and any suggestions what difficulty should I do
because im doing mythic 3 since I’ve reached floor 100
all items are legend only
I want to get eternal items
Thank you for those who can help

Play on VERY easy until you farm enough crystals to make good gear.

some ways to increase Luck:
*Luck affix
*Luck Nature
*Fortune (Heroic)

some ways to obtain Eternals:
*Eternalized set affix
*Kill Mythic boss
*Convert 20 Legend PvP Chests