That's the strategic map. As you level up more that will become more complicated. Food management gets added at level 6, for example. But right now you only have two resources to worry about, blue shards and time units. Blue shards are pretty easy to gather, so until costs get balanced those are essentially free. Time units are specific to each citizen at the bottom.
You can spend blue shards to end the turn, which give each citizen more time units. They get #morale per turn, or 30 in DeeDee Petty's case. Ending the turn also lets raiding parties move 1 square on the world map.
You can spend blue shards and time units to scout terrain. Scouting terrain lets you know if there's anything interesting on that square, like resource deposits or special types of dungeon.
Added: The only trap you really need to worry about happens at level 6, when you can tell your citizens to build things in town. Make sure to keep at least 200 granite to build a quarry. Cedar logs can be harvested on foot pretty easily, but granite is a lot harder to get in the numbers your town needs.