For future assignments you should start your work in your working copy. For those using g++, just move to the appropriate directory in your working copy. For those using an IDE (Integrated Development Environment), start up your IDE, create a new, blank project, and include the files from the proper file location in the working copy.
If you create a new file for a project, don't forget to place it under versioning by using the "svn add ..." as described above.
After you make changes to the file make sure to commit your changes using the "svn commit ..." command as shown above. Do this fairly often as you make logical changes to the program. Don't worry about committing your files too often. If you are using an IDE on MS Windows, make sure to install Cygwin so that you can reissue a commit command easily. In other words, don't wait until you are "all done".
If you want to work on another computer or even in another directory you can reissue the checkout command as much as you want. Just make sure that you have committed your changes from the other system.
Note that the grader and I will be adding files in the "Evaluation" directory. You cannot change these (in the repository), but you can read them. In order to see them you will want to do an update.