MacBook Pro won’t start and won’t charge. The charger show orange and never green.

Is this an older Intel Mac or a new M1 Mac? You really need to mention the exact model Mac when asking for assistance since there can be huge differences in how best to proceed. At first I thought it was an older model due to the Magsafe charger, but then remembered the latest Macs once again have a Magsafe charger. If your Mac won't boot, then you can get the exact model by entering your system serial number here:

Check Your Service and Support Coverage - Apple Support

Try an SMC Reset (Intel Macs only). There is a possibility that the laptop is powered on, but has no display or is frozen. The SMC Reset will power the laptop off in an instant if this is the case and it will reset the laptops power management system if there is a charging/power issue.

If the battery was left completely discharged, then it can prevent the laptop from powering on or even being able to charge the battery.

Here is an Apple article for troubleshooting Magsafe charging issues:

If your MagSafe cable or power adapter isn't working - Apple Support

Could be a completely dead battery. If you have access to an Apple Store, making an appointment would be a good starting point.