We'll come right out and say this - Linux breaks. There, we've got that off our chests. No matter how much we might like our chosen distro, there is no denying that things can go wrong, or that it might not even be right in the first place.
Of course, Linux distros are not alone in this - a computer system is a huge, complex collection of interacting software and hardware, even more so when the basic install includes several gibibytes of extra software over and above the OS.
We can't show you solutions for every problem that might arise, but we can show some of the common issues people face and, more importantly, show you how to go about identifying a problem. One more thing to bear in mind as you're reading is that even if you can't work out the solution yourself, an accurate description of the problem will be of great help when asking others for advice.