Lanette,
What I mean is there is a direct URL on GTT that allows someone to do those registration steps, right? So why not place that into the email?
Marketo won't be able to track more than the click through automatically. You'd have to bring the registrants' data back into Marketo via a list import.
Bedrock can help make this process automatic.
http://www.bedrockdata.com/business-data-management/gototraining-marketo-integrations