Let's get to Grass Cover Camps, an orange quest given by tenebris or by an bookshelf next to him will be available at Lvl 65 and it will start the "Corrupted Records" Quest line which can be really really hard. You will be asked to fight against overpowered SoulWorkers as bosses, don't be scared to die and use revives here, just try to die less as possible since the more you die the more your gear reduce its durability which make you way more weak during the fights.
The order will be like this:
1-Kill Lily 2 Times.
2-Kill Stella 2 Times.
4-Kill Erwin 2 Times.
5-Kill Haru 2 Times.
Those kill instances will be entered by using an book given by the chain quest itself. Just use it when the quest asks you to do.
The second time you have to kill the soulworkers they are more overpowered so be carefull, remember to repair your gear before jumping into it everytime!
After doing that we'll be asked to finish AoV 1 time and can be done in low difficulty so it should be doable. If you don't know some mechs you may die, I recommend you to check its mechanics now because you will be need to do AoV on Maniac after and its better if you start getting used to it. (Or find an friend to carry you).
After this the quest chain will spawn the AoV boss into the field as a friendly NPC, at this time you should interact with him because of the quest but you should also buy the item he sells that gives you some "Desire Fragments", you can buy it everyday, 18 of those are neccessary after in the quest so it's better if you start getting them soon. You can also craft it on that same on that same NPC using AoV orbs, thats up to you.
So, now AoV boss will ask you to gather some item. You will do the last instance of S303 Shelter at dipluze horizon to kill the queen and get the item.
After that, AoV boss will ask you to gather 20 quest items. In the quest description itself tells you exactly where you can farm it:
1-Hidden Hideout, an raid, not recommendable unless you have friends to carry you.
2-Doing last instance of Holy Ground portal at dipluze horizon on maniac.
3-Doing last instance of Dawn of Fate portal at dipluze horizon on maniac.
These are ordered by higher to lower difficulty, and it also gives you less quest items per run if it is less dificult. But I do really recommend farming one of the normal instances to get it instead of doing hidden hideout.