Like most features on your iPhone, CarPlay should be straightforward to use once you get it set up. Unfortunately, as with any tech, problems can arise that stop CarPlay from functioning properly. After you get used to the conveniences of Apple's auto software, you can feel stuck in the past when you have to use your phone's display for music and maps instead. And that doesn't even take the safety concerns into account.
Perhaps you can't get CarPlay to work for the first time, it's stopped working after a period of normal use, or it suddenly keeps disconnecting. These problems often have the same root causes, so running through some troubleshooting should clear them up. Unless the issue ends up being the cable you use for CarPlay, you won't have to spend any cash, either.
One don't have to be an automotive technician or an iPhone expert to apply these fixes, so even novice users should be back to enjoying their favorite music and navigation streamed through the car's display before long.