How can I do the scroll pattern that's on this cake? Do I need to use some sort of stencil? Or do I free hand it? Or is there some other way?
Looks like a stencil that was overpiped with buttercream.
There are so many places to buy stencils! It's possible it could be custom or because it was overpiped it could have started out as a base design that was added to - or it could be 2 different designs put together. I'm going to go out on a limb and say that there is pretty much never a reason to find this exact design when a bride shows you a photo unless you are a couture house that makes custom molds and stencils based on the lace of the bride's $15,000+ dress. Pick something close and go with it. I guarantee you, no bride on her wedding day is going to notice that whatever you used is not this exact design. Trust me!