How to delete files I no longer want?

I have saved files I need to delete.

You can delete any file in the file manager (in your case probably Windows Explorer, Windows key + W). Navigate to the folder holding your files and go for it.

Just in case, after deleting the unwanted files, if they still appear in the LO opening index of documents, just click on the “X” in the upper right corner of the document’s icon to remove it from the LO index.