Can I sue someone who does not have insurance, they hit me from behind?

If they don't have car insurance, then you will likely not be successful in obtaining any funds from them.  You should check with your  insurance carrier and see if you have any uninsured motorist coverage.  If you do, this is exactly what this type of coverage is for - it is to protect you in the even that you are in an accident with an uninsured driver.  Thus, if you have the coverage, you should be able to get compensation from your own insurance company (and there should  not be any type of penalty).  Check with your insurance provider.  Best of luck! NOTE:  This response is general in nature and should not be considered legal advice.  No attorney-client relationship exists or is formed by this response.