Help a noobie

https://preview.redd.it/jiy0mn7zibme1.png?width=3440&format=png&auto=webp&s=51f18b404b6ddaf439979429779a15ffd0922cbd

Having a horrible time with camera angles, especially when using cranes. Can someone tell me what the red filled circles, the blue circles above them, and the blue circle at the bottom mean?