Experimenting is good. That's how you learn what your equipment can and can't do. Take some photography courses online or at your local school. Join a photography club to get feedback from fellow photographers.
Stock is a business. Submit only your best work that has a real chance of making sales.
Professional stock photography isn't taken with a selfie camera. Adobe's customers expect and demand the highest quality, National geographic quality, set up perfection. At the very least, get a tripod and remote. But don't expect to get much of saleable quality from a phone.
That's a difficult task. A helper is most probably required for this to get an acceptable shot. Having someone agreeing to model for this would make it an excellent shot.
ABAMBO | Hard- and Software Engineer | Photographer
We can't assess the technical issues from this tiny thumbnail; but certainly composition is an issue because you've cut off both ends of the object making it difficult to determine what it is.
Common issues that can impact the technical quality of images include exposure issues, soft focus, excessive filtering or artifacts/noise. Learn more about our technical requirements