First of all, congratulations! Now, you need to make sure your work is registered. As soon as a song is published and/or recorded, it should be registered with and reported to BMI. BMI's ability to license and monitor the performances of a composition is dependent upon the accuracy and timeliness of this reported information. Without it, you may miss out on royalties.
Typically, a publisher will register songs for songwriters. Early registration of works will help prevent lost royalties, so make sure your songs are registered.