I have a imac early 2008 OS X Yosemite , how do go bout updating software because from what I see there is none.

For the 20" and 24" Early 2008 iMacs, El Capitan is the end of the line. That's only one major version later than Yosetime, so it might not be new enough to help you with the applications you are trying to run,

You can get El Capitan by following the directions here:

How to download macOS - Apple Support

Just make bootable from Yosemite or El Capitan, by bootable USB drive, plug in and press option key while booting, to go into boot menu. You can download Yosemite App Variant for bootable and El Capitan, and follow steps from Apple support page, for Yosemite you need to app just one more parameter I think

sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ Yosemite.app

Wish Good Luck!