If you have a schematic, then you should start fritzing, then select the components in the schematic (you may have to search for / create some components if they aren't in fritzing) and then drag them in to schematic view and connect the wires to match the schematic you have. Once that is done you can them place and route breadboard and pcb views if you wish. I don't think there is anything that will import a schematic from another package if that is what you are asking.
Peter