I need help setting up Conversion tracking in Google Analytics

I have a client site using WooCommerce with Google Analytics set up. My client wants to track conversions but I'm struggling to set up GA to do this. We have an Google Tag manager account set up and I've tried to set up a tag to track conversions but I'm struggling to understand how it all works.

I need someone who can log into the Google Analaytics and Tag Manager account and set up everything we need to track sales on the site in Google Analytics.