It's important to consider what happens if your work isn't accepted. Despite best efforts, you may get to the end of the peer review process and have your article rejected, or you might not even get that far and be rejected earlier in the process. But that doesn't mean you're out of options for publishing.
You can appeal the publication's decision to reject your work though this is often unsuccessful. Nonetheless, if you decide to go that route, consider the following: first and foremost, what the journal or publisher's policies are for appealing. Then you will need to make a compelling case for your article to be reconsidered and that may mean submitting additional or supporting information and data. However, if that doesn't work, you can always shop around for another journal. And chances are, having done additional work to make your article more robust for your rebuttal means you'll be in better shape when you submit elsewhere.
The reasons for being rejected will likely guide your next steps towards success. If your article did not fit editorial expectations, such as being outside the purview of the journal, you might simply identify a more-appropriate publication and resubmit your article as is. Of, if there were concerns about the substance of your article - incomplete data, analysis, methodology, unclear or unproven hypothesis, or results not supported by the data - you may need to undertake revisions before resubmitting.