Using "submit" as your label? So are thousands of other sites. Your users won't be confused.
Using something more descriptive? That's fine too. Maybe it looks a little nicer and less generic. But it's not a usability problem.
Don't worry about this for a second. Instead focus on the real problems, like creating usable and accessible form fields with associated labels. Write easy to follow directions that explain which fields are required and what format you're expecting (or write better error handling techniques to accept a variety of inputs.) Write and make visible appropriate error messages to help your users through the process so they don't make mistakes. Record the mistakes they make so you can use that data to engineer your forms in ways that reduce user errors.
There are so many other things worth your attention.