The bad news: You do not know if your story is worth publishing. A new author is way too close to the story to get a realistic feeling if the manuscript is "worthy" to be read or published. This feeling comes with time. Once you have finished polishing a dozen books, you may have a better feeling — or you may still have nagging doubts, depending on your personality.
The good news: You can ask readers.
Get beta readers. As a first step, show them just the first few pages. Ask them for their spontaneous reaction and if they would be fascinated enough to try and find out what happens next. If they are, why would they continue reading? If they are not, why would they stop? Ask them about their feelings and opinions, not about craft — craft is what you should contribute, it is not their duty to know it.
You can ask your fellow writers. Look for other authors. Either those that are meeting in real life, say, once a month at a cafe, and have been doing this for years. Google "author meeting (your next bigger city)" or try "author group" — if you find nothing, look for online groups. They can give you more feedback regarding the craft.
A good beta reader may tell you, "I just do not know. If these were the first few pages of a book, I would not have continued reading. It starts awfully slow. And I was mightily confused already on page two."
A fellow author might give feedback for the same text like "You introduce five faceless characters on pages one through six. Each one talks exactly like any other, and calling one 'Deep Voice' and another 'Raspy Voice' does not help much, as long as they all talk the same way. Staying ominous about the topic of conversation can be fine, but you have to do it while raising the reader's curiosity about both the characters and what they are talking about. It seems to me that you believe that readers are obligated to continue reading. They are not. A reader is not automatically fascinated by what you write; you have to make them get interested. Rewrite the first six pages and make each voice individual. Give them character. The reader should be able by page six to recognize each voice both by the way they speak and by their view on the subject."
The reality check for your manudcript:
Ask yourself why a reader who sees the first page would continue reading after the first sentence. Or would they likely pick up the next book, as they are bored already after the first sentence of yours story? Write down your findings.
Repeat this check for the first paragraph.
Repeat it for the first pager
Repeat it for each scene. Yes, each scene of your book. Why would anyone continue reading after that scene?
Imagine that you knew nothing about the book. Write down the bestseller-like qualities about the first sentence, the first paragraph, the first page, and each scene. Read other books you admire to see how other authors did this.
Compare your text to theirs. What do they do differently?
Then rewrite your text to make it more fascinating to the reader.
Repeat all of this for a dozen times. Yes, rewriting your text a dozen times.
Only then get your first beta readers and ask your colleagues for their input. You do not want to come across as The Lazy Author Who Writes Boring Stuff And They Know It right out of the gate.
Yes, many hours of work pile up before you.
If you are not prepared to invest it, just put your text onto Wattpad and hope to be discovered. It worked for some people. Maybe one in ten thousand? Maybe less.
If you consider writing as honest work, continue on the path outlined above. You have a chance of success, even if it is not especially high. The more effort you invest, the higher your chance to get readers like your stuff.
If you view writing as a hobby that makes you feel good, that is perfectly OK. 99% of people who write stories do it for the feeling writing gives them. Then my advice is to not bother too much about your success in publishing. Just enjoy the pleasure of writing.