32 Bit Applications on Catalina?

I have not updated to Catalina as I have some applications which are 32 bit. These are mostly for a scanner and also probably remnants of the many operating systems I've had over the years (I have a new iMac but have been using them since the '90s). How do I tell which are critical and which are not necessary? I won't upgrade until I feel more confident about the stability and efficacy of the OS, but any advice would be helpful.

THANK YOU