Difficulty in converting my note into a pdf

I check back again. The version of Notes I used to determine the PDF conversion was 12.5.xx

I now noticed that on IOS 14.x.x that features seems to be gone.

Another method would be to copy your note into Pages then convert to PDF

Convert Pages documents to PDF, Microsoft Word, and more - Apple Support

When you have the note file open, then activate the share icon (rectangle with arrow up)

There should be an option for PDF there.

Hope this helps