Need some more info...what operating system are you using? In windows 10, if you type %appdata% into the search bar next to the windows logo at the bottom left, you can then locate the Mindustry folder. It will have all of your data. If you put that folder into the %appdata% folder on your new PC you should be able to pick up where you left off.
Hope that helps.
more info about %appdata% - https://answers.microsoft.com/en-us/windows/forum/windows_10-files/how-to-access...