If your clock has a backcover that has a nice pattern to it (rather than being totally flat), then your clock will have a transport lock.
As your instruction manual will show, it is located close to the Quartz clock mechanism and is a sliver, cross-headed pin that is unscrewed and then pulled completely out of its socket. You can use a flat head screwdriver to do this.
Once the Transport Lock Pin has been removed, the clock's batteries can be inserted and the clock turned on.