Hi Joe, welcome to the forum!
There are two kinds of digital images – vectors, which are made up of lines, and rasters (aka bitmaps), which are made up of pixels. Both types can be contained in SVG files.
Rasters can only be engraved. Vector images can be cut, scored or engraved. So you need to create your files in a vector drawing program, such as Adobe Illustrator (expensive), Inkscape (free), Affinity Designer (cheap), etc.
The post below is a good place to get started finding tutorials and tips to help you get further along – if you scroll down a bit you’ll find “the Matrix,” where you can get further information.