You made an unfortunate purchase.
Your motherboard is not suitable for a FX-8 processor.
http://www.tomshardware.com/forum/id-2384024/motherboard-tier-list-970-chipset.html
As above, you NEED a cooler. You will destroy your chip without one.
Anything is better than nothing.
If your case has 160mm height available, a reasonable cooler is the $35 scythe kotetsu.
It cools better than many high end coolers including the noctua NH-U14s.
Here is a review:
http://www.silentpcreview.com/article1391-page1.html
Truthfully, if your goal is gaming, do not spend a dime on what you bought.
FX has slow cores for gaming and there is no upside available.
It is essentially obsolete.
My advice is to resell it for what you can get and start over.