And remember macOS 10.15 does not allow 32-bit apps to run. (Some 32-bit apps may not have 64-bit updates.) Also check your Printer Driver for an update compatible with Catalina.
Here's a clip from Apple's support article on 32-bit apps:

"When upgrading to macOS Catalina, the installer shows a list of recently used apps that are 32-bit. You can review this list before choosing whether to cancel or continue the installation."

• Final Cut Pro X 10.4.7 update (app store)
  - See release notes for long list of changes.
  
  
• Logic Pro X 10.4.7 update (app store)
  - See release notes for list of changes.
  
  
• Compressor 4.4.5 update (app store)
  - See release notes for list of changes.
  
  
• Motion 5.4.4 update (app store)
  - See release notes for list of changes.

• How kernel prelinking works on macOS Catalina (or not) (little snitch blog)
  
  
• Upcoming Security Updates for Adobe Acrobat and Reader (adobe bulletin)
  - Updates scheduled for Tuesday, October 15, 2019
  
  
• Apple Arcade: Unlimited Cross-Platform Gaming (owc blog)
  
  
• Mercury Elite Pro Thunderbolt 3 Dock and Dual-Drive RAID (product page)
  - 2 drive capacity for up to 28TB. (Also see blog post on the new dock.)
  
  
• Critical Security Issue identified in iTerm2 (Mozilla Open Source Audit) (mozilla.org)
  - "All users of iTerm2 should update immediately to the latest version (3.3.6)".
  
  
• Cloning Catalina with Carbon Copy Cloner (CCC blog)
  - Also covers preparing for the upgrade, if/when you should upgrade, and about backups.
  
  
• Logic Remote app for iPad/iPhone v1.3.5 (Requires iOS 13.0 or later)
  - Includes stability improvements and bug fixes.
  
  
• What's new in Photos app in macOS Catalina (sponsor blog)

• How to upgrade to macOS Catalina
  
  
• How to create a bootable macOS installer (updated to include macOS Catalina)
  
  
• About the security content of macOS Catalina 10.15
  
  
• How to update the software on your Mac
  
  
• 32-bit app compatibility with macOS High Sierra 10.13.4 and later
  (32-bit apps won't open in macOS 10.15 Catalina.)
  
  
• (How to) Find out which macOS your Mac is using
  
  
• About macOS Recovery
  
  
• How to reinstall macOS from macOS Recovery
  
  
• About the screens on your Mac as it starts up
  
  
• How to connect to the Internet with your Mac
  
  
• Switch libraries with the Music app or Apple TV app in macOS Catalina
  
  
• If your Mac is lost or stolen
  
  
• What happened to iTunes? (not in Catalina)
  
  
• Use the Finder to sync your iPhone, iPad, or iPod with your computer (Catalina)
  
  
• Sync your iPhone, iPad, or iPod touch with iTunes on your computer
  
  
• Use iTunes to sync your iPhone, iPad, or iPod with your computer
  
  
• Sync your iPhone, iPad, or iPod touch with iTunes using Wi-Fi
  
  
• Get help with iCloud Keychain
  
  
• (How to) Change the desktop picture (background) on your Mac
  
  
• Logic Remote (App) release notes (revised for v1.3.5, requires iOS 13.0 or later)
  
  
• Locate and view your connected device on your computer
  
  
• How to update your iPhone, iPad, or iPod touch
  
  
• If you see an error when you update or restore your iPhone, iPad, or iPod
  
  
• Get help with iOS update and restore errors
  
  
• If you can't update or restore your iPhone, iPad, or iPod touch
  
  
• If you see error 53 when you update or restore your iPhone or iPad
  
  
• What to do if you need more space for an iOS update
  
  
• How to check the storage on your iPhone, iPad, and iPod touch
  
  
• How to back up your iPhone, iPad, and iPod touch
  
  
• How to Restore your iPhone, iPad, or iPod to factory settings
  
  
• If You Forgot the Passcode for iPhone, iPad or iPod Touch or Device is Disabled
  
  
• Transfer content from your previous iOS device to your new iPhone, iPad, or iPod touch
  
  
• If you see a Cellular Update Failed or Apple Pay Not Available alert after iOS update or restart
  
  
• Institutions that support health records on iPhone and iPod touch
  
  
• About the security content of Swift 5.1.1 for Ubuntu
  
  
• About the security content of iTunes 12.10.1 for Windows
  
  
• About the security content of iCloud for Windows 7.14
  
  
• About the security content of iCloud for Windows 10.7

• Firefox 69.0.3 release notes lists 2 bug fixes (not macOS related).
  
  
• Chrome 77.0.3865.120 stable channel update (includes 8 security fixes)
  
  
• (USB 3.0 Type C) ORICO 2-Bay Hard Drive Dock Review (storagereview)
  
  
• Microsoft October 2019 Patch Tuesdays (isc.sans)
  
  
• Security Updates from Juniper Networks (multiple), and Intel (multiple)

September 30th to Oct. 4th, 2019 News Archive
• Safari Technology Preview 93 released
• How to Fix macOS Catalina Installation Issues
• Updates to Pages, Numbers and Keynote apps for Mac and iOS
• Micromat MachineProfile 1.3.10 update (Catalina compatible)
• iOS 13.1.2, iPadOS 13.1.2, watchOS 6.0.1 Updates
• iPhone 6s and iPhone 6s Plus Service Program for No Power Issues
• How to Customize the Finder Toolbar in macOS
• Mac Total War: SHOGUN 2 & A Total War Saga: Fall of the Samurai updated to 64-bit
• Total War: WARHAMMER II - The Hunter & the Beast DLC for macOS
• Apple Denied Tariff Relief on 5 Mac Pro Parts After Staying in TX
• Malvertiser Exploited Chrome and WebKit Bugs to Infect Over 1 Billion Ads
• Firefox 69.0.2 release notes lists 3 bug fixes
• Advisory on Mitigating Recent VPN Vulnerabilities
• Firmware Updates for LG C8P/E8P/W8P and B8P OLED TVs
• Apple Support/How-To/Troubleshooting Article Updates

For links to older news pages, see the Archives.