Your barracks are the way to make troops for battle. Uprgrading them fully will have the ability to train: Barbarians, Archers, Goblins, Giants, Wallbreakers, Balloons, Wizards, Healers, Dragons and P.E.K.K.A.s. The cost of troops depends on what level the troop is (upgraded in labatory).

 Town Halls: Your town hall is the heart of your village. Upgrading it will unlock new content for you to put in your village. Put your town hall in the middle of your village to avoid it being destroyed because you will lose one star to your enemy and lose trophies. The maximum level for a town hall is level ten. Your town hall can hold 1000 gold and 1000 elixir.