should I update to Sonoma on my Mac

Some people choose to update right away while others choose to wait for a while. There is no right answer for everyone. Here is what I do. I have an external SSD disk connected to my computer on which I install newly released operating system upgrades. I keep the already installed older OS which is installed on another SSD. Then I merely change the startup disk to the new OS. If it works good, I will eventually delete the other older OS. If I don't like the new OS, I go back to using the older OS until a new OS update is released which performs as I want it to. This avoids having to erase a HD in order do downgrade its OS.

It's up to you. Without knowing your reasons for using a Mac no one can answer that question for you.

Always have a backup plan in case something should go awry, which just goes without saying. To learn how to use Time Machine please read Back up your files with Time Machine on Mac - Apple Support. Having a backup is totally unrelated to upgrading macOS itself.