Practice and playing guitar should be fun and challenging for newbie or guitar master. Practice should be done with specific goals in mind. I know tons of guitarists who think they are practicing but what they are really doing is just playing.
Playing is important too but practice is something different. What you practice should come out in your playing. If it doesn't, you're not practicing efficiently. Before you sit down to practice, make sure you know what goals you are trying to reach by practicing, short term and long. It may even help to keep a log of your practice sessions. When, how long you practiced, what specifically you practiced and why you practiced it. The goal must come before the process is determined.