I am not entirely sure what exactly you would like to import, here are some options...
... you can import a whole survey project (which will delete anything that is currently in the new project)
... you can import sections and/or questions (just download as XML and import in the new project) without doing any harm to the existing contents in a project.
... you can import a CSV file with collected data, as long as the variable names and response codes match the new project.