If you do decide that you need more features, Logic Pro provides a ready-made upgrade path on the Mac, as much of the functionality is the same and GarageBand projects can be loaded into it. The effects library includes virtual guitar amps and stompboxes, and there are enough editing and mixing features for you to polish a track to completion. There are plenty of rhythmic and instrumental loops, too - just drag them into the Timeline and start creating - and Apple’s excellent Drummer enables you to create customised drum tracks to fit your projects.
Not only can you record audio - your guitar or mic, for example - but you also get a strong selection of software instruments that can be played from a MIDI keyboard. And guess what? It makes it ridiculously easy for pretty much anyone to start making music. The most famous free DAW of them all comes bundled with every Mac and is freely downloadable for iOS devices.