A: Possibly. You can try to import them, but there is no guarantee of full compatibility. Many users have reported that projects from the older 32-bit version do not translate perfectly to the 64-bit version on Catalina. It is highly recommended to export your old project stems (individual tracks as audio files) before switching systems as a safety net.
macOS Catalina strictly enforces 64-bit architecture and notarization security. Older 32-bit audio plugins will not work. Ensure your virtual instruments and effects are updated to 64-bit versions compatible with macOS 10.15. Conclusion garageband catalina 10.15 7 download
Are you getting a when you try to install it? A: Possibly