Combat modules provide automated turrets and cannons for your base. When your base gets attacked from enemies or other players, those combat modules will defend your base with whatever weapons are attached to them. Research new guns in the Arms Lab.
Research modules
Keep your research modules upgraded in order to have the latest research options available. Researching will give you access to more powerful equipment, stronger weapons, and better armor for your ships.
Resources
When low on resources, send your fleet out into space and search for loose cargo containers. When found, your ships will shoot them open and allow their resources to be collected and brought back to base.
Space battles
Try to be efficient during space battles. Rely on focus fire strategy that was demonstrated during the tutorial. To do this, tap the "Select All" button to select all your troops. Then, tap an enemy ship to have all of those ships fire on that target. If AI control is on, after that enemy ship is destroyed all your allied ships will automatically target the enemy that is closest to them. You will have to manually re-target to focus fire on another enemy ship. When one of your ships takes too much damage, pull them back and position an undamaged ship on the front line.