I participated in a single convention out of state, and filed the Georgia FS-32 Miscellaneous Sales Event form. Do I need to file a State Return in Georgia?

It depends-

Nonresidents, who work in Georgia or receive income from Georgia sources and are required to file a federal income tax return, are required to file a Georgia income tax return. Some examples of Georgia source income are wages, Georgia lottery winnings, income from flow through entities (s-corporations, partnerships, LLC’s, trusts, and estates), rents, etc. If you are a legal resident of another state, you are not required to file a Georgia income tax return if your only activity for financial gain or profit in Georgia consists of performing services in Georgia for an employer as an employee when the compensation for services performed does not exceed the lesser of 5% of the income received in all places during the taxable year or $5,000.00.

Filing Residents, Nonresidents, and Part-Year Residents - FAQ