Andy's reply is perfect.
The range is limited at East Lake, and they call you to it when it is your turn, so use all available time to go through the clubhouse carefully. If you love the history of the game, you'll be blown away by what you see. Excellent selection in the pro shop as well, and if you buy anything, they'll have it waiting in a locker for you at the end of your round. Get all your calls out of the way, because your cellphone will be turned off AND will be in a locker the entire time you are there.
It is walking only, and, as Andy says, let your caddy read your putts for sure. There is nothing tricky about East Lake; it is classic, understated GCA. While we all know about the renovations over the years, the fact is that you will be walking where the gods have walked, so enjoy every part of the experience.
As to the weather, it was about 65 here earlier in the week. The high today will only be low 40's, but then we're back up to mid-50's tomorrow. By late Feb., high school golf has already started here, so you certainly have a shot at a decent day. Really, the odds are that rain will be a bigger problem than cold, though anything's possible, of course.
As to other courses, in the ATL it all depends on where you are staying, how much you are willing/able to drive, and how much access you have. Tell us those things, and the ATL contingent will make suggestions, I'm sure.