It will also be important to read other books in your own genre and try to observe the market a bit yourself. Perhaps one recognizes a trend. If you come up with a book about vampires now, you're probably a little late. That would have been great 10 years ago.
You don't have to copy other authors, but you should learn from them. How do they build characters, how do they build a story...? You learn all that in such workshops.
You could also meet with other authors. Maybe there is a kind of book club only for authors. There are also training courses in the field of writing. Maybe that would be a good idea, or you could go to the university and listen to some literature lectures.
I also read a lot, but not to copy from other authors, but to be inspired by their stories and also to reflect on which elements of the writing style I like well and which I like less. I think the knowledge and skills could also be well honed in a workshop. To see what my chances are, I contacted Novum Publishing with a sample of my book. I got feedback from the service publisher that they could see potential and that I should keep at it. I can contact them again when I am finished with my work and then they will see how they can support me on the way to publishing my book. However, I'm sure it will be some time before that happens. I've made good progress, but there's no end in sight yet. And when I'm done, I want to give the book to a few beta readers first and get feedback, and then start editing it myself. I think that will be a good piece of work again. But I'm looking forward to when the story is ready to be polished before handing the project over to professionals.