It's a drawing.
The steps are:
1) Draw it
2) Scan it
3) Manipulate it in either Illustrator (converting it to vectors will make it infinitely scalable without pixelation) or Photoshop (which might be more comfortable for you)
Many ways to tackle this.
In Photoshop - a very quick conversion :
A curves adjustment to bring out some contrast then a smart filter and the Filter Gallery - Graphic pen
The paper texture was just a layer filled with colour and Filter - Filter Gallery - Note paper applied
The top layer was set to blending mode "Multiply" to let the paper show through