Is it a Classic I or a Classic II?
1) Go to the Apple menu in the upper left corner of the screen/menu bar. Choose the first selection on the list, and report back what the version is. It could be running 7.0.1 or 7.1 (I don't think they had 6.0.8L in Italian, but I could be wrong, and that's only for the Classic II and four other Macs). You will have to reinstall the System Software to change languages.
2) Recap or have the motherboard recapped by someone else. While it is apart, clean the floppy assembly (but do NOT touch the heads) and apply an extremely light coat of grease (moly-based is fine) to the assembly. Bad caps can also affect the FDD as well as...#4...
3) Networking, a SCSI CD drive, a SCSI HDD, floppies, SCSI Zip drive, SCSI tape drive, or the serial ports.
4) See #2...
You should take the unit apart and inspect the motherboard. Don't worry it's a small board. Inspect for damage on the board, although if all you have is no sound (assuming it's not muted) and a flakey FDD it could be just time for routine capacitor replacement and a floppy drive cleaning.
See the second link in my signature for networking. The first part of the More Info page describes how to install system software. Fix the capacitors and floppy drive, then you might want to make a System 6 Emergency Network Access Disk -- conveniently, I have already made some in the Download Town section.