Well you can search to see if something already exists that will work on sites like Bambu lab or thing verse.
To more easily create your own file: you could use Bambu studio. It allows you to right click the build plate and "add primitives" as well as burrow into solid objects, to generate objects fairly easily
A simpler option could be their online tools, like "make my vase" but these may not be advanced enough to do what you need