By url you need a tracking pixel on your landing pages. I believe that is only available on premium. However, you can use unique creative that is targeted on a specific page, this will allow you to do a report by creative and make sure your targeting is very unique.
Having built several teams, there are a few things to do before you start hiring. Identify what you want to build, what is the culture you are trying to build, be specific, don't just say casual, efficient, fun. The more details the better. What is the expectations of a new hire? Dress code, hours, delivery, social events, hobbies, etc... I've learned that side projects and hobbies allow you to learn more of what people like to do rather than the interview answer. It is also helpful to ask existing employees what they think your culture is. An executive perspective is often skewed, unfortunately. The people who currently work with you need to be candid. It is critical to build trust early to get the right people. Other things to consider, work life balance (what is your priority? ), food accessibility, alcohol in the office, smokers vs non smokers, break schedule, problem solving skills, persistence to a problem. Good luck in your team building!