The terms "After Effects" and "live" are mutually exclusive. If your goal is to have AE render in real time, dream on. To get render times to speed up a bit, going to faster processors helps, and 16 GB memory is pretty good.
An Intel i3 sounds like a processor, not a graphics card. An i3 would be a fairly slow processor.
After Effects relies mostly on the processor for rendering. It also needs a good bit of RAM. A good rule of thumb is to have 4 GB of RAM for every core of your processor.
A graphics card is fairly irrelevant for After Effects unless you're using the (obsolete) ray-traced renderer or third-party plugins that use the GPU (such as Red Giant Universe, Element 3d, ShapeShifter, etc.).
Sorry, I mean processor then. Well I only have a dual core, so 8GB will meet that rule of thumb. So upgrading my processor to something like an i5 would help?
Well, you also have to reserve some RAM for your computer and system processes, so you don't have 8 GB for After Effects. Bumping that up to 16 might help somewhat.
Upgrading to a different class of processor is usually not possible without getting a new motherboard and that starts getting complicated quickly. It's often easier to get a whole new computer. If you do that, you could get an i7 with 32 GB of RAM (or more)!