I am working in a project to design a wireless charging device. I need to design a square coil and fabricate it on PCB but i have no idea to start with the software. Using the software, what should I do. Whether i just need to use the traces to form the square coil.
If you've calculated parameters, I.e. Trace width, number of turns, width, height, layers, etc, then you just need the connector on a schematic and turn that into a board with one giant trace, shaped how you want. Watch out for issues with trace heating and current capacity, there've been issues with that on some square coils I've seen in the past.
If you need to calculate those parameters above, eagle is not the right software to do that in.