Last name???

Anna • Wife and mother to a sweet baby boy ❤️ 🍾👶✨

I’m thinking I want to hyphenate my last name instead of change all together to my husbands. Does anyone know if you’re supposed to do it in alphabetical order? Or does it not matter? I don’t care either way just want to do it right...also, which one would my son use? I put his dads last name on the birth certificate because I had planned on changing it, but now that I want to hyphenate I’ll probably have to go change his too? Or do I only hyphenate my name and my boy takes his dads last name? Does anyone have experience with something like this?