OK, so I'm new to 3rd person shooters and action games generally having mostly played Dragon Age and Final Fantasy of late. I'm really struggling with combat. I tried the mission to find Liara straight after the Citadel and cannot get past the ambush which includes a geth armature! Part of the problem seems to be that my squad won't take cover when I ask them to (down on the d-pad right? I'm playing PS3). 

Any tips on how I should improve would be really appreciated. For now I'm just wandering the galaxy trying to up my XP first... Playing as a soldier by the way.

d'oh! thanks.

Having finished the main story, I've just got the paradox ending by beating Atlas without having weakened him first. But now when I go back to the historia crux, I can only access Bresha Ruins (005AF) and the paradox ending. Does anyone know how I get back my access to the other locations I've unlocked? I really don't want to play through the early stages of the game all over again!