@dynabook, OSX Catalina is now no longer an option, Big Sur is the new kid on the block.
As long as you ensure your applications support 64bit and you update drivers for printers/scanners etc you should be fine.
I installed Big Sur today on my iMac and it does seems lightning fast compared to Mojave. I spent time yesterday ensuring my software and printer/scanner drivers were up todate.
You may find this of some help:
https://www.stclairsoft.com/Go64/
Install and run it and it will show you which of your software etc is compatible for 64bit computing.