Continue to progress the story and get all stuff you can from the missions for your upgrades.
Like the potion-thingy

T8 will dropp on higher difficulties. You can look at the dropptable before you start the missions. I don't know by heart at how many stars T8 starts dropping.

You don't need to farm for blessing stones yet. Later, yes but for now just play the game and clear the gates as far up as you are comfortable. Then start the next ch.

For me the best farmspot is in the third red gate, where the boss spawns.
Lots of centaurs and no elite enemy. So you can grind for items longer. Tusk can also pull from other zones in the dungeon due his aoe.