iPod shuffle music loading issues

I have a shuffle (2nd gen, I believe) and I wanted to put a new playlist in it. I thought I added my songs (only 600 mb out of 1 GB used), but it will not play anything at all when I try to listen to it. Fully charged.

When I look at the songs, it seems different looking, in terms of the appearance of the list of songs. It s a mix of MP3 and MP4 songs.

It also does not have the synch ability anymore. It stays gray. Same with devices, it does not come up dark so I can use it. Stays gray in background too. I can't even open it to restore it to factory blankness.

Any ideas ? Thanks !!