KiCad is a free and open-source electronics design automation (EDA) suite. It features schematic capture, integrated circuit simulation, printed circuit board (PCB) layout, 3D rendering, and plotting/data export to numerous formats. KiCad also includes a high-quality component library featuring thousands of symbols, footprints, and 3D models.
Please find a comprehensive overview of the typical process involved in designing and fabricating a Printed Circuit Board (PCB) in the following link.
In the next two links, you will find a tutorial featuring a basic circuit that illustrates the process of designing a PCB: