I am building my first pc it is all put together except for my fan that goes over the cpu. I bought the cpu thinking it was coming with one but it didn't. I have been searching the web for one but I cant seem to come across a fan just for my intel core i3 2120. If someone could help me out that would be great!
If you bought a CPU that did not come with Intel's stock HSF you much have gotten an OEM ('tray') chip.
HSFs are sold based on which socket(s) they are intended to go with, not by specific CPUs. In your case, you would be looking for LGA1155 HSFs. Since i3 uses very little power, just about any HSF should do.
The Hyper 212+ for $25-30 is a common recommendation and would be total overkill for i3. The main problem with it is that it may not fit on some motherboards and may also be too tall for some cases.