Entry points to the webpage

As @thelearningproject mentioned, there are many types of CTAs... are you taking about say an external campaign CTA (i.e. cid=123 or utm_campaign=123, etc) or are you talking about a button on your site that is a Call to Action (to make a purchase, or sign up for something etc).

If the first (external campaign), let's suppose you are using the campaign tracking codes (which have a default 1 week attribution) and you want to see JUST the entries. You can actually use the metric "Tracking Code Instances" to get just the entries.

Think of campaign codes in this way:

(External Site with Campaign Link) > Page 1 > Page 2 > Page 3....

Page 1 will track the campaign code, it will also trigger the tracking code instance

Page 2, 3, etc will all track the campaign code too (since you want to attribute purchase successes, signups, other conversions, etc to those campaigns), but because these values are maintained through attribution and not "direct tracking" they will not trigger the instance.

If you want to see all pages/actions from a campaign, you can use Page Views, Visits or Occurrences etc to see everything, Purchase Success or Cart Additions, or custom conversion events to see what conversions are attributed; and you can use the tracking instance to see where the tracking was directly tracked.

If you are trying to see the page where an internal CTA button was clicked... OR the first page of the visit that lead to that internal button.. its similar.

You should be able to again get the button clicked actions and correlate to the page... that is pretty simple... but if you want to to get the user's entry page before clicking an internal button, you would need to pull in the metric of your "internal button" clicks, and pair it with "Entry Page" or "Entry Dimension X", this should correlate the entry page for the visit to the button click.