Resources to study ads, split testing, and metric measurement?

I have an interview coming up for FB ads team. Recruiter mentioned questions will include increasing business through ads, helping them grow, measuring effect using split testing, and metric measurement. Any idea where I can go through this? I checked out few random videos on YouTube to get a sense of how businesses promote themselves through ads. Any fb folks willing to help me out by providing insights on what metrics fb measures and how it performs split tests would be awesome.