Be aware the Juneteenth Celebration is that entire weekend and is held down at Centennial Olympic Park. That park is in the same area of downtown as the Aquarium. Expect traffic to be very bad as the celebrations will spread throughout that area.
https://www.juneteenthatl.com/
I'll also suggest Porsche Center - for certain a meal (make reservations) to gain entrance and watch the track activity even if you don't participate.