Hi Andrew,
It is Visits Web Page that triggers the click on the ad. I label it clicked instead of "visited" because the visitors had to have clicked the ad to visit the landing page (whether it's from the keywords search or from the display network. Then the other is "Trial Requested" which is the same as Converted when they fill out the form. Same thing we do with our LinkedIn ads. Since this is your first run with PPC, pay attention to your keyword quality score which looks at the following: Expected click through rate, ad relevance, and landing page experience. I pause anything below 5/10. Have a keyword in your ad. And know where to find the keywords that are triggering your ad. If it's not relevant add some as negative keywords.