You can copy a project to the current class and/or to one or more of your other classes.
To do this, go to the settings menu on the individual project page for the project you want to copy. In the modal, you will see the names of all the classes you can copy to, including 'This class' (the current class) and/or any of your other classes.
Copying a project will copy the project details and associated code files, but it will not copy any student work associated to the original project. The copied project will be hidden from students by default in the classes it is copied to.