Is there an upgrade of LibreOffice? How do I access it?
Last time 32-bit LibreOffice binary package for macOS was offered to users was in v. 4.3.7 in 2015. Since then, all you could download from LibreOffice site for macOS was 64-bit.
Please visit this official download page to get 64 bit version for Mac OS. I advise to use 6.2.8. version as more stable, have had a few minor issues with 6.3.3 on Catalina just today, while 6.2.8 runs perfectly.
Also since this is Catalina, see → LibreOffice and macOS Catalina