Everything comes from pre-existing materials. Not nothing. How can "creation" make sense if something comes from something, and not nothing? We would be giving pre-existing materials a different shape or form, right? At what point does something new come to exist?
Philosophically, something begins when it fulfils the requirements of its definition, so a morphing thing can take on various forms until such time as it becomes whatever we’re interested in, such as a planet rather than a cloud of dust. The definition is a human construct and so it’s whatever we say it is.