"sude" isn't a thing, he probably meant "sudo".
As for the difference between su and sudo:
They list some of the advantages of using sudo instead of su, but don't list any of the numerous disadvantages to disabling the root account and granting a regular user unlimited sudo power using their regular password, which irks me a bit.
I don't believe Fedora enables sudo by default, which is why it didn't work. You would need to edit /etc/sudoers to grant sudo access to your user before you could use it.
As for adding blank lines between output, you can use echo:
$ cat script
echo line 1
echo line 2