I need help opening Applications With MacOS Catalina

Which Apps are they, did you know about the no more 32 bit apps thing?

Caution on 10.15, to see which Apps will no longer work in 10.15 get Go64...

https://www.stclairsoft.com/Go64/

If MS Office apps, Look into the Free LibreOffice, it handles MS Office files…

https://www.libreoffice.org/

Gregory_Dolmaian wrote:

Oh well, Can i go to Mojave or something then?

Revert your Mac to a previous macOS version - Apple Support

It is up to the developers to create 64 bit versions of their apps.

What applications?

You had to have backed up before you upgraded to Catalina. You need an external drive in order to do a backup.

You should always have a current backup if you are going to use a computer.