The steps to design PCB for multilayer are to obtain the circuit diagram of your project and then calculate the required number of layers you need in your PCB design, based on the requirements of your project. After that generate a board layout in Altium Designer software and check if all components are placed properly on the PCB, before proceeding further with designing the PCB for multilayer. You may get templates by visiting https://masterbundles.com/templates/presentations/powerpoint/animal/ source. After checking all components are placed properly, create an outline of the top and bottom layers using the Auto-Sketch tool in Altium Designer software. Mark out all layers using their respective footprints in Altium Designer software and generate a drill file for drilling holes for mounting components like resistors, capacitors, etc., which will be used on the top layer(s).