it only show the battery charging symbol.
If you only see the battery charging symbol, that indicates there is no data connection between the iPod and MacBook. There is a power connection.
If you have not already, do a Reset (restart) on the iPod.
Learn how to reset your iPod - Apple Support
Disconnect all USB devices from MacBook. Connect MacBook to its power adapter, so that it's not running on battery power. Run iTunes and connect iPod to a direct USB port on MacBook, by itself. If MacBook has multiple USB ports, try them all.
If there is no change (iPod still just shows battery charging symbol when connected), put the iPod into Disk Mode
Putting iPod into Disk Mode - Apple Support
Connect it to MacBook in the same way. And difference?
If no difference, there are three key possibilities:
- Problem with USB port. Try something else on MacBook's USB port(s), such as a USB flash drive, to confirm port(s) working.
- Problem with USB docking cable. The cable may be damaged or worn out, and only connecting for power (not data). If possible, try a different cable to rule out faulty cable.
- Problem with iPod. For example, iPod's dock connector may be damaged or worn out, and only connecting for power; visually inspect dock connector for debris blocking connection points.