I currently have several spreadsheets in the excel format that I would like to save to Libre Office
Simply open your files. When saving with Save As... select .ods in the line for file types next to the bottom of the dialog that opens. Save. Done.
If you want a batch conversion add the information to your question by editing it.
There was a follow-up question: https://ask.libreoffice.org/en/question/237422/lupp-answered/.
From that question it seems the user wanted to ask “Can Excel save a spreadsheet document to the native format of LibreOffice (.ods is that)?”
I’m glad to not have had to use any Excel for decades, I therefore only know that some versions of Excel claim to be able, but I neither know which versions that are nor whether the claim is trustworthy.
I would assume the better result will be achieved using LibreOffice. MS shouldn’t be expected to put nuch interest in well working export to Calc. They make their living with incompatibility, after all.