Just so you know, you're not limited to the floppies that came with the system - you can download disk images from online archives such as
Asimov and write them to Apple II-readable 5.25" disks.
The program used for this is called
ADTPro. It's a Java app (so it will run on any modern computer with a Java runtime environment - PC, Mac, various UNIX/Linux) that transfers the disk images to/from the Apple II using a serial connection. It's an extremely well-written utility that's been worked on for several years; I've been using it mostly to create images of disks that were not already on Asimov, in the interest of preservation. Considering the number of disks that you got with your system, it may be worthwhile to see if you have anything that hasn't already been archived.
If this sounds like something that would interest you,
here is how to set up the cabling for your //c and
here is how to actually get ADTPro going. The initial setup is a bit of work, but once that's done, it's really the easiest thing in the world to send disk images back and forth.
Enjoy your //c! "Apple II Forever"!