If I remember correctly, the area on the left side of the game screen is 'end game' stuff. Once you beat the final boss, you should be able to talk to Memoria and it should open that area up. There are some post game quests and crafting you can do.
The area on the right side of the game screen is tied to your corruption level. You need to have Soul Corruption 1 (you need 10 or 15 soul corruption to reach level 1) and then talk to Memoria, she will unlock the area for you and you can craft 'corruption' gear and items, tied to your corruption level, and you can unlock some Dark based engrams.