What is sentencing like for a first time offender with a 7th degree possession of a controlled substance (cocaine) charge in NY?

Yes you need a lawyer. Beyond that I realize that this answer will not make you happy but it is the most that can be said on a forum like this. I see many questions on avvo in which people want to do what is going to happen to them because of such and such an offense or parole violation. In truth no one except your lawyer can even give you an approximate answer to that question because it depends on so many variables: your state’s laws and procedures, your criminal history if any, whether there are any sentencing enhancements, whether your state has diversion programs for your offense. These kinds of questions really require that you contact a local lawyer and even then they can only give you a range.