Serious answer, everyon WANTS to do it but, if you have to ask that you are definitely not capable on doing it.
I strongly disagree with this.
In the 3DS scene i wanted to make my own CFW, but didnt know jack squat about coding to begin with. After a year or so i learned a ton about coding, and I was running a CFW all customized to my needs (only 1 and 1 person have it).
For the poster: i found that if you truly interested in building your own CFW, current developers are more than eager to help. The "arrogant" developers in the 3ds scene helped me a long way with stupid and diffucult questions.
But for now i would start with making a simple Hello world, and inspect current CFW (like reiNX and Atmosphere) also learn about the switch's architexture (the ARM manual if I am not mistaken).