Learning how to play the guitar was probably one of the best things I've ever done. You don't have to be "amazing" to learn some of the best songs and have fun with your friends singing around a campfire.
Buy yourself a chord book (any music store will have them) and learn these chords :
D, C, G, Am, Em, E, and F.
With those you can play just about any song out there (it's true). Pick a simple song with 2 or 3 of those chords and start to sing it, just strumming the chord once when there is a chord change. Once you get faster at switching between the chords, you'll be able to learn a few strum patterns.
From there you can play, have fun, learn more chords, and expand your song base.
Good luck and have fun!