When first starting, you will be protected from attack for two days. Use this time to build resource producing buildings and silos first, then upgrade them to the maximum amount. Complete single player missions until they are exhausted for resources. Save your Medals instead of spending them to quicken resource production. Medals are better used to get a third builder later. After your resources are set up, build your barracks and upgrade your troops. Increase your Headquarter levels then finally build as many defenses as possible. Position to protect your resource buildings.