In Strategic Mode you build your cities, increase your forces and advance your technology. Tactical Mode is where combat takes place. Energy is required to maintain the structures in your cities.
Credits can buy structures and units.
Research increases the technological level in different technologies. From the Starting menu you begin a new campaign, choose the race you will play and the difficulty level of the game. Name your colony, click start and the game begins. Each game starts in strategic mode with the two enemy capitals separated by neutral territory. You may also play the Last Hope Campaign where all the territory other than your home province belongs to the enemy.