Hi,
To start you need to install Google Tag Manager so all the tracking can be handled in one place, including the ecommerce transaction tracking.
If you are interested, I can help you get that set up in a couple of days, then we can focus on the events that you can measure to better understand the impact of different marketing channels (source/mediums) on the conversions.
Same goes for Transaction Tracking with Enhanced Ecommerce. This can be done through Tag Manager, and we can discuss this further if that is something you would like to see in Google Analytics.
Please let me know your thoughts and if you have any questions for me.
Best regards,
Zee