An IV is put into the arm prior to surgery, but is not left there, permanently; it's removed when surgery is done and before you go home.
Is there something else they're putting in your arm? If so, what is it and what's it for?
Calcium levels are brought back to normal by having you take a calcium supplement by mouth. Has anyone discussed this with you and told you what you will need to do?
They will be removing the works and putting a peace in my arm
Are you having parathyroids removed, as well? Do you know how many of the parathyroids will be removed? It's unlikely you will be released from the hospital until your calcium levels (controlled by parathyroids) are back to normal...
Usually a day. May be longer if there are complications.