Shooting Star Hydrangea
Shooting Star Hydrangeas are beautiful plants for the holidays. They are a type of big-leaf hydrangea (H. macrophylla), hardy in planting zones 7-9, so yes they can be planted outdoors in your area. You will have to wait until after the last average frost in the spring to plant it outside. This is typically around late April/early May. https://extension.umd.edu/hgic/topics/spring-frostfreeze-dates-maryland
Until then, keep the hydrangea indoors in a location where it will get strong light. Water it regularly, but let the top half inch of soil dry out between waterings. If your plant came with a decorative foil or plastic covering around the pot, remove the covering or put holes in the bottom of it so that water can drain through.
In early spring, you can set your plant outdoors for a few hours and then gradually set it out longer each day to get acclimated to outdoor conditions. This is called "hardening off." Here the process is described for vegetable seedlings but it is a similar process you can do with your hydrangea to get it acclimated to outdoor conditions. https://extension.umd.edu/hgic/hardening-vegetable-seedlings
Plant the hydrangea where it will get some shade. Morning sun and afternoon shade would be ideal. They like rich, moist, acidic soil. They prefer to be in soil that is kept evenly moist. A layer of mulch (2-3" deep) placed over the root system will help to retain moisture. Avoid putting mulch directly against the stem(s).
Good luck and enjoy your new plant!