os.rename(), os.replace(), or shutil.move()

All employ the same syntax:

import os
import shutil

os.rename("path/to/current/file.foo", "path/to/new/destination/for/file.foo")
os.replace("path/to/current/file.foo", "path/to/new/destination/for/file.foo")
shutil.move("path/to/current/file.foo", "path/to/new/destination/for/file.foo")

• The filename ("file.foo") must be included in both the source and destination arguments. If it differs between the two, the file will be renamed as well as moved.
• The directory within which the new file is being created must already exist.
• On Windows, a file with that name must not exist or an exception will be raised, but os.replace() will silently replace a file even in that occurrence.
• shutil.move simply calls os.rename in most cases. However, if the destination is on a different disk than the source, it will instead copy and then delete the source file.

myFile.renameTo(new File("/the/new/place/newName.file"));

File#renameTo does that (it can not only rename, but also move between directories, at least on the same file system).

Renames the file denoted by this abstract pathname.

Many aspects of the behavior of this method are inherently platform-dependent: The rename operation might not be able to move a file from one filesystem to another, it might not be atomic, and it might not succeed if a file with the destination abstract pathname already exists. The return value should always be checked to make sure that the rename operation was successful.

If you need a more comprehensive solution (such as wanting to move the file between disks), look at Apache Commons FileUtils#moveFile

Files.move isn't like the command line. You're programming. You have to spell things out. You're literally asking Files.move to make it so that target (here, G:\GoHere) will henceforth be the location for the file you are moving. If you intended: No, the target is G:\GoHere\TheSameFileName then you have to program this.

Separately, your code is a mess. Stop using java.io.File and java.nio.Path together. Pick a side (and pick the java.nio side, it's an newer API for a good reason), and do not mix and match.

For example:

Path fromDir = Paths.get("G:\\FromHere");
Path targetDir = Paths.get(G:\\ToHere");
try (DirectoryStream ds = Files.newDirectoryStream(fromDir)) {
  for (Path child : ds) {
    if (Files.isRegularFile(child)) {
      Path targetFile = targetDir.resolve(child.getFileName());
      Files.move(child, targetFile);
    }
  }
}

resolve gives you a Path object that is what you need here: The actual file in the target dir.