Ok so basically I was in solitude watching a guard shoot arrows and take them from the target and Serana was getting in the way and so I took her to a corner and told her to wait, and when I was done, I went to the the drunken huntsman because I heard you could get a bunch of arrows from there and I forgot to get serana. The I went back and she was no where to be found. I couldn't find her in fort dawnguard either. Is there a certain place in fort dawnguard I should look or what? (By the way, I'm playing the Ps3 version). Any help would be appreciated thanks

She should still be there, but has been known to wander. Have a good look all over the city first.

I'm still a pretty big noob to skyrim, but I thought if you tell her, or any companion for that matter to wait, then they'd stay there or at least within a few feet. Oh well. I guess I'll try again in the morning. I'm kinda to frustrated to get back on right now.

Serana is different than most folowers. She'll wander around and interact with various things.

Alright, like a said, I'll check it out later. Would she enter a building or anything like that?

I've never known her to enter a building, unless you also enter the building. She does have some bugs though. Most notably, she sometimes will not follow you again if you ask her to wait. If that happens the only solution is to revert to a previous save.

Serana interacts with the environment so it is unknown where she will be if told to wait.

Give it 3 in game days and then try fort dawnguard again, usually does the trick when she goes walkabout.

Funny thing is sometime you can meet her randomly wandering skyrim after you told her to wait or dismiss her.

You can ask er to follow her again in this case.

As for your case, sometime she glitched out where the game doesn't render her again after you told her to wait. You have to wait for her to show up on her own or revert to previous save.

She'll show up when you least expect it.