Is there a way to skip a song while the phone is locked and being charged

Tap the home button either once or twice and you will see the music controls.

Double-tap the home button and the play/pause and forward and backward buttons will appear on the screen. Just tap forward, skips the song currently playing.

If you are using the included "earpods" (or older ear buds) you can double press the play/pause button in the headphones cord to skip to the next track too. Triple pressing that button is the "track back" button to skip you to the beginning of the current track, or the previous track if at the start of a track.

Your Welcome.