While it's still easy to use, Apple has kept adding cool new features to Garage Band. Sure, you could invest in some amp emulation software, but if your budget is tight, use the onboard amp simulation! Let's say you added a guitar track, but it doesn't sound quite right. Double-click the Track Header to access the Track Info window, then Click-drag it to sit under your track in the timeline. When you're in Real Instrument mode, select "Guitar" from the list on the left. On the right you should see the default, which is off. Try selecting from the list of amp simulators on the right. One of them is almost certain to please you. Once you've zeroed in on the perfect sound, you can save the project so that the next time you open it, you'll be at the same place in the list of variations that include Arena Rock, Clean Jazz, Dreamy Shimmer, and many more!