In They Are Billions you will have to construct a lot at the beginning. You have to setup Fisherman and Hunter Cottages to arrange food for workers, you have to setup Saw Mills and Tesla Towers for Energy, etc. Ample of the region during the start is locked and if you are unable to find the exact place where to place buildings to get max food or max items then you can turn on Flat Mode. A mode where you will see the ground in grid mode. Green grids are the areas where you can place buildings while black is unexplored or locked region. This will save your time in placing the structures at the corners.
How To Enable Grid Mode / Flat Mode
Press F4 from your keyboard to enable Flat Mode or press the middle mouse click. You will see the green borders the grids where you can place buildings for constructions. This one is pretty helpful when you are placing buildings around the corners of the unexplored or dark region. A lot of space can be utilized in this way.
Construction is an important element in They Are Billions, buildings like Tents, Saw Mill, Cottages, Tesla Towers, etc are needed to make your colony stronger that will later unlock Soldier Center from where you can get Sniper, Soldier, and Ranger.
To know the current stats of your colony watch on the right corner, you will see a face icon, food icon, gold, and energy icon. It will show you the current amount of resources you have stored. With time you will be able to get enough to summon trained soldier who will defend the colony from the incoming zombie horde.
Also slowly explore the dark regions around, don’t push your soldiers to go deeper. There are always zombies in a group or a few standing in the dark. Once they spot your soldier they will attack, so it is best to go slow at the start. Unless you have a fully functional Soldier Center, you can summon as much as you want depending on the sources you are producing.