Hi and welcome to the overclocking sector!
You do have one major drawback, you have a 970 chipset, which is not the best for OC, which it never really was, though your board is a slight exception. You have the right Cooler for OC as well, and I would suggest a good and safe overclock would be 4.3/4.4 Ghz, and nothing significantly over, as said again, it is not designed for overclocking and you could do an unstable overclock. If you go to around 5Ghz, you can and will damage hardware and it isn't covered by warranty, so stay on the safe side!