So I'm at the part where I need to take Aela her shield. She then says to follow Farkas and he'll lead me to where I'll be staying, but Farkas is not in the room. The quest will not continue unless he's there. The quest marker is still attached to Aela and she just says the same thing over and over again. I've seen videos on how this quest is supposed to work, and in the videos, Farkas is there. I tried turning the game off and on, but it still didn't work.

as per most of similar glitches in the game, load an earlier save ...although you may also try deactivating the quest, wait for 3 full ingame days using the wait function (select button) and see if he shows up then....

and also, you can just go find farkas somewhere else in the building and just talk to him, maybe that'll work too