Single party instance (minimum level required is 85, but since Teredor is 88, you've got a bit of a disadvantage with 85 ppl with no attribute), no quests required. There's a daily quest requiring to kill Teredor to get some proofs.
I personally wouldn't do Terredor with people below 87 who don't have at least 3x60 attribute gear and a +3 150 Apoc Weapon at the least. Wiping in there and having ot run back is FTL and the groups I've been doing it with have been flawless to the point where we could chain run it. Once you experience that, anything less is unacceptable.
Solo Options are Altar or Evil and Swamplands (the early part, dmg penalty on Assassins/Watchers/Disciples maybe). Altar can be really good if you can avoid spots full of Summoning MOBs. Otherwise it's a major PITA. NCSoft really increased the HP on those MOBs. They take like 30-40% more damage to kill than before. I went there last night on my Feoh, killed like 3 MOBs and left immediately. Not even worth it if you aren't a Summoner, IMO, unless you absolutely cannot find groups.
SoA Nursery is also doable, and of course you should be doing Kartia solo daily, otherwise you'll get left behind by everyone you do or want to play with (after a month they will be 2-3 levels over you if you don't do the Kartia Dailies, which will put you out of range for the places where they want to XP in many cases).
Group Options are SoA and Harnak. I personally prefer SoA to Harnak, but Harnak is more sympathetic to groups of low intelligence or gear quality. Harnak is good if you PUG a lot. SoA you have to be more careful. Generally avoid Croak if you want to actually XP for a decent amount of time. That's where the badly geared group hoppers go to get their daily quest done. Basically they're there for 5 minutes for the quest then you leave, so you're constantly looking for replacements (spend more time doing that than XPing there).
There's also GoG, but damage is severely off at 87/88 in that place and it's not worth it unless you're trying to farm drops (Twilight, etc.).
Fairy Settlement low side used to be doable at that level but NCSoft basically doubled the MOB HP there so it's not worth it anymore... The Lower XP/Mob was easily countered by the rate at which you could kill them if you knew how to pull them tactfully :-)