Try an SMC Reset (make sure to read the directions carefully as they are different from other older models).
Unplug the charger from the electrical outlet for a minute to reset the charger's internal circuitry. Also try using another electrical outlet.
Try using another USB-C port especially on the other side of the laptop. Rotate the USB-C connector of the charging cable 180 degrees upside down...while this seems odd, it may work if the USB-C port is half bad. This is only an attempt to charge the laptop and narrow down the problem....if this works, it indicates a hardware issue which will need repaired.
Here is an Apple article for troubleshooting USB-C charging issues:
If your USB-C power adapter isn't charging your Mac laptop - Apple Support
If you need to take the laptop to Apple or an Apple Authorized Service Provider, you should also take along your charger & charging cable to make sure one of them is not at fault.