Is Catalina still OK to use cautiously?

I have a late 2013 27" iMac with SSD and 24 G RAM and it performs and works very well (now I regret that I once bought an older model for my first mac! I started only using it late 2015 😕): I cannot upgrade to a newer os. 

Is Catalina still ok to use if use it cautiously? Any security tips there? There are many recent vulnerabilities in many new Apple operating systems but are these affecting the Catalina? No security updates available at this point in system settings... 

I use this Mac for work, coding and stuff. Browser is Chrome and Email client is Edison Mail.

At this point I cannot buy new Mac... And this works great. 

Thanks in advance!