www.bmi.com and www.ascap.com Performance Rights Organizations.
www.harryfoxagency.com Mechanical Licensing.

BMI and ASCAP are Performance Rights Organizations, PRO's.
You join one or the other to track 'Performances', collect Songwriter Royalties and Publisher Royalties.
You might join the same one as a Publisher you have signed with.
If you are the Publisher you can Register your Publishing company name, the Titles of your Songs, the names of the Author(s), Composer(s) and their 'shares' of the Copyright. www.copyright.gov

There have been some changes in recent Law. I forget just what they are, some 'new' 'entity' that can track things in the new mode of music consumption, streaming, downloads, stuff like that, I think.

Transitioning from 'avocational hobbyist' to 'commercial entity', engaging in commerce with the public, and other companies, requires that you study a little about things you may not have studied before. A little study at copyright.gov, reading Circulars, can Educate you so you can take care of yourself to a degree. An Entertainment Lawyer may be necessary if your situation and comprehension of it is too complex for you. Entertainment Law has nuances of difference from Criminal Law or Commercial Law so not every lawyer may be informed on your needs. A little consultation may be a good investment.

There will always be another song to be written. Someone will write it. Why not you? www.garyeandrews.com