Luna Diviner7

I'm sorry, I'm not really sure if I fully understand what you're saying. So I need to create a Pokemon save file on my computer, alter it using pokegen, then transfer it back? Can I just use my Black file, or must I have a preexisting file on my computer?

I have a few questions and need some help with stuff that I haven't seen on google or this site. My first question is, can I use this with a 3DS? I really have no idea what I'm doing with this Pokegen thing, I've read several different things and I still have no clue what I'm doing. I keep reading about an R4 flashcard; what is that and where can I buy it? I'm essentially looking for a complete, start to finish explanation/guide of what to do. I have no Pokemon file on my computer, etc. I've searched for hours, so hopefully I'm not over looking something. Please help? I'd really appreciate it.