Ever made a daisy-chain? British culture #shorts

The video introduces a field full of daisies, reminisces about making daisy chains as a child, and explains the process of creating these chains. It also introduces Jacob, who has been playing football, and Caspian, who is experiencing FOMO instead of napping.

Who is Jacob and what has he just been doing?

What does FOMO stand for and how does it relate to Caspian?