The punishment for theft by deception depends on multiple factors. The threshold factor is the amount of the alleged theft. If the amount is $500 or less, then the punishment is as a misdemeanor. If the amount exceeds $500, then you can be looking at a felony conviction. There are multiple factors in the statute that determine the range for the sentence if convicted of a felony. In Georgia, the sentencing ranges are very broad (i.e. 1 to 10 years, 1 to 15 years, 5 to 10 years, etc.). Without more information regarding the details of your situation, I can't give any more specific information as to what range will apply.
You can do a search for these statutes: OCGA 16-8-3 and 16-8-12. These address theft by deception and the associated penalties. I would copy the text for you, but the statutes are lengthy.
It is unclear from your question whether this is your first felony charge ever, or if it is just your first theft by deception charge. If you have never been convicted of a felony, you may be able to take advantage of Georgia's First Offender Act. There are pros and cons to using the FOA, and it is highly advisable that you discuss this option with an attorney.
Because you are potentially facing serious felony conviction, it is very important that you discuss your entire situation with an attorney. You need legal representation.
This is given as general information and does not create an attorney-client relationship.