Drone Question?

https://federaldroneregistration.com/georgia-drone-registration.

In the state of Georgia, it says I don’t have to register my drone if less then .55lbs. I will be flying a Mavic Mini to start with. It has a weight of 0.549 lbs. I know I have to be license to do contracted work with a drone. My question is, I got certified with InterNACHI today to help me with getting my license when I’m ready. So can I practice with the drone not having anything right now for my mock inspections with permissions from the home owners “aka my neighbors.” I want to follow the S.O.P. Also anyone from Ga. that uses a drone would love some input on that or best practice.
Oh last thing on a commerce property can I fly a drone off the roof with landing pad? I’m very knowledgeable about commerce roofing due to my time working as a commerce tech just was trying to get all the facts. Thanks again, well back to learning.