I am uploading my gerbers onto freedfm just to check it, but it asks for X and Y Dimensions? What am I supposed to put in here? My PCB is designed as a half circle. Also, how do I know how many layers my PCB has?
Top copper would be one layer, bottom copper is another layer. Most PCBs have at least two copper layers and a drill layer. Apart from that you can choose to have soldermask and silkscreen.