Since you are a beginner, I wouldn't be too concerned with tab or sheet music. One thing worth focusing on, at this point, is your technique and learning a few basic chords and concepts concerning chords. Tab and sheet music are, at least, a couple of months away.

If you haven't already, I would consider getting a good teacher or instructor -preferably someone who plays the type of music you like or would like to play. That way, you can see where your playing should progress in time. Also, I'd read everything about playing guitar that you can get your hands on - magazines, websites, books, etc. Don't worry so much about difficult or little-understood concepts, but focus on a few of the basic elements that keep showing-up in your readings - they keep coming-up for a reason.

And, remember, practice, practice, practice. You gotta practice to yield results. You may not think so or see it very plainly, but consistently good practice over a period of time does, in fact, yield results -maybe not huge results all of the time, but results nonetheless. Persistence is key.