Recruitment is also a crucial aspect in your Base's development. Your troops can be used to gather resources, explore the map, defeat encounters, protect your allies and yourself against outside offensive actions. In other words your troops will be the main engine to push your progress forwards.
Troops can be recruited from the Military District using the available Recruitment queues which you have at your disposal. Initially, you start with a single queue, but additional ones become available as you upgrade your District. Also in order to unlock higher troop Tiers you will need to level up your District as well.
To begin recruitment tap on the Military District and then select Recruit from the given options.
A list of unit will be displayed including the still unavailable units. On the top of the interface you can select what Type of unit you wish to train. Different types of units have different use, some can carry a lot of resource, others can traverse the map quicker. You'll have to decide how you'll use each one for your goals. Once you've picked what do you wish to recruit, simply tap over it and then select the Recruit option. The unit will be added to the recruit queues as from there on you'll just need to wait a bit for it to finish.
You can always speed up that process by tapping over an active recruit queue to display the Speed Up pop up interface. Don't forget to check the Unit Stats to see whats the difference between each one.