is it even possible to update my 2006 apple desktop to recent programs like sur?

In a word, no. Your 2006 can only go to 10.11.x, if you have a need for later versions of Mac OS then you need a newer Mac. Your 2006 simply does not have the hardware (no it cannot be upgraded) to support more current versions of Mac OS.

A 2006 iMac doesn't run 10.11. It maxes out at 10.7 Lion