I fresh install Catalina. But I don't like it. I deleted and install Mojave again. I don't like that;
1-File system very solid. No change anything.
2-New iTunes (called Music).
3-Can't use Office 2011 for Mac. And many 32 bit apps.
Sounds like you didn't do much research, since #2 and #3 are well known changes that come with Catalina that have been discussed in Apple circles for months.
For #3, I am even more curious. Perhaps cost is an issue, but why not move into current times and use Google Docs or something else in the cloud like Office 365 that supports the same MS Office file formats? Or, if don't like the Cloud and want a disconnected desktop application installed locally that supports these formats, why not try LibreOffice or another freeware office suite for MacOS that provides updates?
Just to note: "Microsoft has announced that support for Microsoft Office 2011 (Word, Excel, PowerPoint and Outlook) for Mac is ending October 10, 2017. ... This means that no more bug fixes or
security updates will be coming from Microsoft and they will no longer help you with any issues you may have if you're still running Office 2011."
I am also curious to know what 32-bit apps folks are still using on MacOS that don't have modern 64-bit replacements?