Since you're a soldier just take cover and shoot. Soldiers get every weapon in ME2 so you have a range of shooting options. Shotgun for close combat, assault rifle for medium range and sniper for distance. Use adrenaline rush to line up head shots with the sniper.
said do Archangel's mission next as its required anyway. The galaxy opens up a little after that I think. You don't have to deplete every planet of resources just get enough to fill your meter. You can find side quests on the planets by scanning when edi detects an anomaly.