Ogeecheedawg,
Welcome to the forum. Most likely the write protect slide on the SD card got accidentally moved to the locked position. Just slide it back and you should be fine.
However, I do recommend purchasing a better SD card like the sands extreme III. The perform extremely better when recording on the unit, and tend to be much higher in quality.
Do some searches here on the forum for SD card and you will find a lot of good reading.
Hope that helps.
Robert