how do I save and plant a plum seed? I'm mildly confused.?

I know that I have to expose the kernel and put it in water under really good lighting then transfer the seedling to a pot of compost. This raises my first question. What kind of compost? My mother and I keep a compost pile in the back yard, but do I need only a specific kind of compost? My second question, I read that a plum tree needs a lot of space. How much is a lot? a square foot a square yard a square mile? how many feet by how many feet do I need? My third question, I read that they need to be held up or drafted what does that mean? How do I do that? Ok last question, apparrantly some varieties are not fertile and need another plum to pollinate. Does that mean I need to just plant an entire plum in the ground, or do I plant two seeds? Can someone please explain these things to me?