Female dogs often go into their first heat cycle while they are still puppies. Many veterinarians will recommend spaying your dog early so she doesn’t ever have to go into a heat cycle. Exceptions would be for large breed dogs who often go through at least one heat cycle before spaying, so their bodies are allowed to grow properly before cutting off the hormones responsible for both heat and growth. Another exception would be a to-be mother. If you are breeding your dog, she may go into several heat cycles. Keeping her clean will help her smell good, feel good, and keep her private areas sanitary.
She might be a tad irritated. She might be agitated. Your dog in heat might be a bit uncomfortable and potentially more tired than usual. You might find her curiosity leads her to lick often. Just keep an eye on her and keep her as clean as you can.