When you charge your MacBook, does it matter which thing you plug in first?
Apple recommends to plug the adapter into the wall before connecting it to the computer.
For more information, refer to the Apple Support article, Using and maintaining your Apple MagSafe Adapter.

Connecting the MagSafe Power Adapter to power
Make sure that the AC plug or AC power cord is fully inserted into the power adapter before plugging the adapter into a power outlet. And be sure to plug your adapter into the wall before connecting it to your computer.