So far I have been using TinkerCAD which has them but I am unable to find them on EasyEDA Library. Are connectors supposed to do the same thing? I get this empty rectangle in the EasyEDA library which I am unable to make sense of.
EasyEDA is not designed for diy prototypes like TinkerCAD is. EasyEDA's purpose is to simulate electronic circuits and design circuit boards for those circuit designs. Because of this they don't have a breadboard object because there would be no point in having one, since you can just connect virtual wires in the schematic mode and wire traces in the board design mode.
Furthermore, it doesn't support simulating a full Arduino board with code.