Catalina software

Hi, just purchased a new MacBook Pro (13-inch, 2019, 2 TBT3) a few days ago and I haven't done anything yet with it because I am concerned about the installation of the macOS Catalina sofware. I have been reading some reviews on youtube, and it seems that 32 bits apps won't work with Catalina. My question is: since my computer is new, I would like know if the existing apps on my Mac are already 64 bits or do I need to upgrade them to 64 bits prior to install Catalina. thanks All.