Session->NewSession->FolderCompareLoad a source folder by dragging it with the mouse and dropping it on the left side, anywhere. Load a destination folder by dragging and dropping it to the right side. On the left side, with the mouse, left-click to choose your folder(s). Then right-click the mouse for this context menu:
Session->NewSession->FolderSyncUse right-click if you want to turn these arrows on/off (1). Each arrow is a prediction toggle of which files are about to get copied. When you are ready, press SyncNow button (2). There is no undo, so maybe try a few small test files first.