If you're new to guitar and know just a few chords, check this site out
https://play.riffstation.com/
Create an account (free), and then enter any song title or band you like. Riffstation will show you the chords in a simple way, letting you play along to your favourites.
It's not perfect - it makes some mistakes and the resolution isn't that tight for faster playing, but its still a fun way to get you started.
You can go more advanced by downloading Riffstation to your computer. It will play any song in any format including Apple itunes, and show you the notes being played. You can speed up or slow down the music, narrow the bandwidth, build riffs, repeat sections, etc. Really useful program.