In this Series of lectures I will be lecturing to develop the Calabi-Yau Spaces. These are Especially vital to String theory Where we consider a space time of 11 Dimensions. In this part of the series I will be majorly focusing on the Complex Geometry, where I talk about Complex numbers, planes & Manifolds, here I will develop the Higher Dimension definition of the Square root of negative one. Finally, We will look at the general tensors to elaborate the higher dimension definition of the imaginary unit in terms of eigenspaces and eigenvalues of the almost complex structure.