Getting Started Programming NDS or GBA Homebrew

[Bowser N64]

Hi. I just recently decided to learn C Programming. I use the program Dev C ++. I also opened up Programmer's Notepad, a program included in Dev Kit Pro install package. I want to know if I am able to use what I program in Dev C++ and paste that into Programmer's Notepad to make an GBA file binary. I mean, is the text I make in Dev C++ and Programmer's Notepad interchangeable, as in, I can create a GBA or NDS, etc. binary from what I make in DEv C++? What all do I need to even get STARTED making homebrew for my GBA or NDS? I downloaded Dev Kit Pro I THINK. I have dialup internet and it seems a fast download. Is the Dev Kit Pro folder really that small? I used the Dev Kit Pro Updater 1.4.7. I was expecting many megabytes of files. Did I get all I needed? And how will I know? Thanks, and I hope somebody could help me on this all.