As you learn how to play the guitar better, there is just more and more information to grasp. Advanced guitar techniques vary based on the styles you are trying to master, but many of these will be something you can try to look forward to learning.
Harmonics
Harmonics at first are rather difficult. An harmonic is a very interesting sound that you wouldn't expect from a string. If you hold a finger from your left hand over a string and don't push down, then lightly pluck with your right hand, you will get a harmonic sound. It's strongest over the 12th fret and fairly strong over the 5th. These used properly give amazing new sounds to music. Many acoustic guitar players let them ring out while playing on other strings.
Tapping
Tapping is where you strike your finger between two frets and it makes the sound. You can do this with one hand, or even two. With two handed tapping you can simultaneously play notes on every string of the guitar. To me this is kind of like playing a piano, where you get to hit only six keys at once. Many great songs and riffs can be made from one handed and two handed tapping.
Finger Picking Styles
There are a wide variety of finger picking styles which you can pick up that will totally change the way you can make your guitar sound. These are a bit more advanced, since you will start to really challenge your strumming hand like you haven't before.
Effects Pedals
There is a wide range pedals available for guitar players. Some are just on and off, while others you have to press up and down on a pedal. When you are playing your guitar, getting good with your feet is a skill that needs to be learned. If you haven't practiced standing up, that's the first step. Then build your coordination with your feet.