If you are working on a new feature, you should checkout from dev branch and name the branch as feature/branch-name.
After finishing your task, merge your current branch into the dev branch by creating pull request
If you are fixing a bug on a development environment, you should checkout from dev and name the branch as bugfix/branch-name.
After finishing your bugfix, merge your current branch into the dev branch
If you are fixing a urgent bug on a production, you should chekout from main branch and name the branch as hotfix/branch-name
After finishing your hotfix, merge your current branch into the staging branche by creating pull request.
Then test your changes on the staging environment, if it's OK, then you must merge changes with dev and main branches.
This section has moved here: https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify
