Are the carts that come on the attys usable or are they dummies?
Every 510 atty I've bought has come with carts that are completely usable. I just filled mine with aquarium filter media and that's that. Well, unless you count the debate over what makes the best cart stuffing. Lots of threads in the
510 sub-forum about that. I suppose some people like to keep an empty cart on the end of their extra atties to protect the internals from ... something. Dust?
Also, I'm guessing the eGo is still shipping with incorrect charging instructions. If not, then hurrah! With LiIon batteries, there's no need to do an intial 8-hour charge, followed by some other "conditioning" charge, or any other arcane battery rituals. LiIon batts should have appx. 40% "storage" charge in them for, uh, storage, so it's likely your eGo batts are partially charged out of the box. You can vape right away after cleaning the primer fluid out of the atty. Some people (such as myself) like to do more than just blow it out, because you can't get it all out that way. I do a PGA rinse. As far as your batteries go, when the green light comes on, they're charged, and there's no need to leave them on the charger any longer.
Congrats on getting started vaping. Main thing to know is that it's a learning experience. Lots of juices to try. Lots of accessories. It might take some fiddling about with cart stuffing, different juices, and who knows what else, before you hit what feels like your "sweet spot", but once you do, you'll discover how much better vaping is than smoking. (You might discover that right away, for that matter).
The other thing is that while many people switch right over to vaping and never look back, many also have a relapse here and there. I tapered down on my smoking while increasing my vaping over time. Had a few relapses as well, when I was at work with nothing but dead batts. (The eGo will save you from at least that issue, unless you get very absent minded with keeping your spare charged.) Don't beat yourself up if you have a smoke. Just keep on the path to your goal.