You're going to need to update the bios. Try going to a local micro center, buying the compatible CPU and upgrading the bios. Then return the CPU back to microcenter and buy the one you want.
instead of buying a new motherboard and the i5 couldnt i just get an i7 6700k or an i5 6600k?
you can do that it just that usually the motherboard is the cheaper route to go.
thinking you have the right BIOS won't do you any good if you end up finding out the CPU won't boot with it and end up getting a skylake CPU just to update the BIOS
On their homepage it says that my motherboard supports the 7600k with f20 bios. and i havent really had this motherboard for long either, built this pc in january. It was my brother that installed all the parts and such so im assuming that i have the f21 bios. I guess i could just ask him to be sure