I only know Intel chipsets so can't speak for AMD, but if you are running on k series chipset i.e. i5 6700k you can overclock it, it will not do this automatically, and if you are on a non-k chipset you cannot, (well you can but it is a lot more complex so I wont get into it.) In addition, your motherboard has to support overclocking, if you are using a big box store computer you most likely won't be able to. You will know if you can or not if you go into your BIOS and see options to change CPU volatges, DRAM frequencies, core ratios, fan speeds, etc. If you don't see those those options and don't have a K series mobo you are SOL, if you do, I can help you OC your PC if you want.
Edit: If you are running a stock cooler on your CPU I would advise against it also as OCing creates additional heat on the processor.