All CPUs will need a CPU cooler or else the PC won't boot. The CPU will simply overheat very quickly and shut down before damage is caused.
A lot of the time, a stock CPU cooler is provided within the CPU package. Since your CPU is unlocked (name contains a 'K' on the end), however, it requires an aftermarket cooler as it doesn't include a stock.
For no overclocking I highly advise the Cryorig M9i for $20 USD. It performs very fine for no overclocking, noise levels are low, and is smaller, better ram clearance and easier to build with unlike the cooler master 212 Evo.