Yes, the police can arrest you even though you didn't leave with the items. How sad that you had to steal using someone else's car.
I would recommend you avoid that store in the future. Not only did the employee get your friend's license plate, you were likely later identified on surveillance recordings in the store, so they have a picture of your face. Those images have a tendency to make their way to the police, to the news, and to Facebook, etc. Now, will the police show up? I don't have a crystal ball, and all you can do is wait and see. And worry.
Whatever your "reasons" are for stealing, you'd better find a different way to live going forward.
Hopefully, your friend will ask you to find another place to live. I wouldn't keep a thief in my home, especially one that used my car to commit a crime. If you think my comments are hateful, but you don't think stealing is hateful, then I recommend therapy.

