Nice will be going for this myself mate, done bloodborne and ds2 so why notim only 15hrs in atm mind, at the boreal valley atm, seems a much more interesting area
I think this is the easiest one to 100%, although getting the rings is a little tricky and there are pyromanceries/rings locked behind the deepest covenant allegiances. Assuming the online works okay for you, don't do what so many people are doing and farming mobs for the covenant items, they are all 2% chance to drop at the most, like proofs of concord from Silver Knights for example. You're much better off just becoming a blue sentinel for 30 anti-invasions as it's much faster and more fun.
Although some people are having big issues with a few covenants like watchdogs and sentinels, so if you're one that never gets summoned (isn't user error, you're either f'd or you're not) you will have to farm them.
Tongues/Sunlight medals/shackles shouldn't be an issue, you can get both by invading with the right covenant equipped. Best place to get tongues IMO is to equip Rosaria Fingers covenenant and put a red soapstone down outside Boreal Valley boss, I've gotten 10+ tongues in one summon from clearing out fight clubs people host. Sunlight medals/shackles you can get doing the same with WoS/Mound-Makers equipped or by putting your friendly summon sign down outside bosses ofc, with Mound-Makers being better off putting their summon signs down at bonfires if you want to acquire them through PVE and not from player killing, as PVE Mound-Makers can only get shackles through killing enough mobs, they can't fight bosses. Although Mad Phantoms can attack/be attacked by the host and white phantoms so that's something to look out for.
Either way:
Concords (Sentinels/Darkmoon) = Silver Knights, farm the 3 leading up to Aldrich from the bonfire
Wolf grass (Watchdogs) = Gru monsters in the swamp, farm the 3 outside the bonfire
Dregs (Aldrich Faithful) = Deacons in Aldrich area
Pale Tongues (Rosaria Fingers) = Darkwraiths, before Abyss Watchers is the best place
Shackles (Mound-Makers) = Giant skeletons in the catacombs
Sunlight Medals = Lothric Knights
Only do these as a last resort though, as like I said the drop rate is 1/50 so on average you'll have to kill 1,500 of each monster to get the 30 needed!
1,500 Darkwraiths can take days.Tried to keep that as spoiler free as possible, but the covenants are the hardest/most time consuming part of getting 100%
