I live in Kentucky and I have an apartment connected to my garage, I was considering furnishing it and using it as a vacation rental. I was needing to know if there is any laws that need to be followed or do I need to get a business license, any information would be helpful. Thank-you

While of course you always need to clarify this with your city ( where you get business licesne) but in general you don't have a license to own rental property.

The isue is how you are going to do the "vacation" rental. If it moves to a more boarding house or a bed and breakfeast things, then you may well.
If it is more of a weekly rental then normally not