Don't panic. Take a deep breath and start here.
Brand new to playing the guitar?...read this first.
Then scroll down the main page to Kirks' beginner lessons then Nelsonites strumming lessons. Kirks tune lessons are next. Just surf for an easy one to start with. Read some of the posts and you will find many tips and suggestions on which tunes to work on. Ask questions, the good folks here are always ready to help.