According to
georgiapacking.org, here is Georgia law on use of force in defense of habitation:
O.C.G.A. § 16-3-23
Use of force in defense of habitation
A person is justified in threatening or using force against another when and to the extent that he or she reasonably believes that such threat or force is necessary to prevent or terminate such other's unlawful entry into or attack upon a habitation; however, such person is justified in the use of force which is intended or likely to cause death or great bodily harm only if:
(1) The entry is made or attempted in a violent and tumultuous manner and he or she reasonably believes that the entry is attempted or made for the purpose of assaulting or offering personal violence to any person dwelling or being therein and that such force is necessary to prevent the assault or offer of personal violence;
(2) That force is used against another person who is not a member of the family or household and who unlawfully and forcibly enters or has unlawfully and forcibly entered the residence and the person using such force knew or had reason to believe that an unlawful and forcible entry occurred; or
(3) The person using such force reasonably believes that the entry is made or attempted for the purpose of committing a felony therein and that such force is necessary to prevent the commission of the felony.
You would need to see how Georgia law defines "habitation" to see what places this covers; but I would be surprised if it did not cover apartments.
I was wondering if the apartment is under my name, am I allowed to have the weapon inside my apartment and ready to use if need be?
Check out the above link, they may be able to provide state-specific info for you. If you are over 18, then there is no federal law barring your possession of a firearm (assuming you are not a prohibited person, which since you filled out a 4473 for a gun I am guessing you aren't).
After that, you need to check state laws and then whatever your apartment lease may say about that issue (see the similar thread in here concering guns in off-campus apartments:
http://thefiringline.com/forums/showthread.php?t=486355)