Your will probably have difficulty getting clearance if you have a robbery on your record. However, this question is outside my area of practice. I suggested you ask Christine McCall this question. I will also move your question to the licensing sections.
The above information does not establish an attorney client relationship nor is it meant to provide legal advice.
You have a difficult challenge ahead of you to cause the State to allow you the privilege to work as a CNA at this time. In general, State licenses, certificates and credentials are very difficult to obtain if there is criminal history (misdemeanor or felony) and especially if the criminal history involves allegations of drugs, alcohol abuse, violence, sexual or child abuse, theft, fraud or misrepresentation.
Your capability to obtain State certification becomes less difficult over time (so long as there are no additional offenses during that time), but 2 years is usually not considered by State administrative staff to constitute a sufficient period of time to show rehabilitation.
If you can work at steady and responsible employment, stay drug-free, and avoid any further criminal offenses (even arrests), in another 2 - 3 years you will be in a stronger position to apply.
My responses to questions on Avvo are never intended as legal advice and must not be relied upon as legal advice. I give legal advice only in the course of an attorney-client relationship. Exchange of information through Avvo's Questions forum does not establish an attorney-client relationship with me. That relationship is established only by individual consultation and execution of a written agreement for legal services.