War

Declare War and War Of Independence
Declaring wars is the most common action you will use. It allows you to annex territories bordering you or provinces that are on a different landmass  but that are connected to your first province on that landmass  (assuming you already have one).

Casus Belli
First of all you will have to pick one of 11 available casus belli. Some of them are blocked until you fulfill a certain requirement be it having claims or being the biggest country around. These casus belli are as follows:

Propaganda
Secondly you will have to pick your propaganda.Some of them are blocked until you fulfill a certain requirement.