First, Carla, I notice that this is your first post here at Helpful Gardener.
Welcome to the forum! See if there are other questions/discussions helpful to you, esp. in Hydrangeas.
There are lots of species of Hydrangeas; you may have a Hydrangea macrophylla (originally native to Japan/China) or a H. arborescens (native to eastern US).
Many hydrangeas can be made to change from pink to blue, if that's what you prefer, by manipulating the pH (acidity/alkalinity) of their soil.
If you'd like specific care instructions for your region of Tennessee, I'd suggest taking a picture of your new plant to a nearby independent nursery/garden store and asking them for recommendations.
USDA Zone 9, Sunset Zone 17