Hi Jessica:
Based on the scenario you describe, there are three events that you can track:
1. They click on the lilnk in your email
2. They visit the landing page (which is a direct result of the above; therefore it might not be worth tracking separately)
3. They fill out the form
You can create listening campaigns for each of these activities, if you like - but you need to have corresponding progression statuses in your Channel, so you can record this progress.
Providing the progression statuses have been added to your channel, your campaigns would be:
1. SmartList: Trigger (not filter) "Clicks Link in Email" (specify the email and the specific link you are looking for), then Flow: "Change Status in Progression" to: "Clicked".
2. SmartList: Trigger: "Visits Web Page" (specify the landing page you are looking for), then Flow: Change Status in Progression to: "Visited Landing Page" (this requires a progression to be added to your Channel, if you really want to track it).
3. SmartList: Trigger (not filter) "Fills out Form" (specify the form and the landing page it is on), then Flow: "Change Status in Progression" to: "Converted".
To reference a landing page you built in Marketo - you don't have to use its URL - just use the Marketo asset name, which consists of the Program Name that the landing page is in, a "dot", and the name you gave the asset inside the Program.
Hope this helps!