Welcome to the group.
I hate to put it in these terms, but you have some big problems with your anemone. It's not attaching to anything, it's not expanding properly, and it's bleached. This is going to be very difficult to impossible to save, even under the best of conditions. Note that even in it's best picture the anemone is still very retracted with a really tight base. It's also white, indicating that it's bleached. Notice on the picts on the link
@nanoreefing4fun showed your that the anemones are brown.
If possible, return it to your LFS. If not, I'd discard it. This is not going to end well, and in my opinion your better off cutting your losses now, before it completely dies and risks fouling the tank. I know that not what you want to hear.
To be successful with anemones you need to have a well established system with excellent quality water, good filtration and water movement, and excellent lighting. It usually takes at least a year to get to that point. In looking at your pictures, I see the tank looking somewhat cloudy, and a lot of algae and cyano on the rocks. This would seem to indicate less that ideal water quality. The lighting also seems to be very dim, but this may be because of how the lighting was running when you took he pictures.
Trying to quarantine an anemone in a breeding box doesn't help either, because the anemone is not getting the water circulation it needs. However, if you try to put it in the main tank, it will get blown around and likely end up in the filter intake doing a lot of damage to it.
If your still going to try and keep it, maybe you can find or make some sort of small plastic cage to place over it and put it in your main tank. Keep it in dim light for now. Keep an eye on it. If it seems to give off and "smoke" or shows any decay, or smells really really foul, it'd dead. Get it out of there.
Now I know this post seems like I just ripped you up one side and down the other. I don't intend to do this, but your far better off hearing this than telling you something like hang in there, it will be OK. If it's any consolation, just about everyone, including myself, that has been into reef keeping any length of time has made similar mistakes, and had their system crash on them.