It is part of the game. It is supposed to help alliances whose leaders went inactive and make coups viable. Only put members you trust in any officer position.
You need to build a power plant to build barracks to recruit troops. To do that, go to your "Cities" page on the sidebar. (Link) Then select a city where you want to build the improvement. (For you, here is Manila and Makati.) Then scroll down and click on the "Power" tab and build a power plant. I'd suggest an oil power plant because of your size and continent. You will need oil to power it, so go to the "Resources" tab and build an oil well. Then go to the "Military" tab in the city screen (not sidebar) and build barracks. Then go to the "Military" tab on the sidebar (Link) and recruit troops.
To do all of that, you need at least 50 infrastructure per slot. If you did all of that in one city, you would need 150 infra. I'd suggest you join an alliance.
WISD0MTREE's post in Heirs becoming leaders on their own. was marked as the answer