Until you have at least 100 conversions, with conversions defined as billable call. You should be running "link click" or "landing page view" objectives to draw in traffic to your lander. Then once you hit 100 conversion, ADD a "conversion" objective campaign. We recommend still running "link click/landing page view" objective campaigns even when running "conversion" objective campaigns - this ensures continuous flow of relevant data to the pixel further helping the algorithm.