There is a lot of really great stuff in Apple’s new macOS release, Catalina (macOS 10.15).
But there is also a lot changed that can cause problems.
I strongly recommend you wait until the first major update (likely macOS 10.15.1) before upgrading to macOS Catalina.
If you do decide to upgrade to Catalina, be sure to take all the usual extra precautions, especially to make a full image backup of your main boot drive. Right now, my recommendation is Carbon Copy Cloner (CCC) which has a new version available that works with Catalina. (SuperDuper, my other long-time favorite, has not yet (as of this writing on October 8th, 2019) released a version that works with Catalina.)
The makers of CCC have written a great blog post, which also explains a bit about what is changed in Catalina that makes it complicated to support and why having a fully bootable backup is essential for safety. (tl;dr – it’s the only way to go BACK to Mojave.)
I always recommend maintaining a fully bootable backup that’s updated on a regular basis, but before this Catalina upgrade, it really is absolutely essential.
For a full review of macOS Catalina, check out MacStories: