okay so i'm borrowing this game from my cousin for a little bit just try give it a try.
I'm trying it a little and so far it's obvious that I suck at this game

(i'm not coordinated enough for shooter combats). Having said that, I picked Sentinel. Is there another class I should restart as that might be easier to manage? Or (in terms of control scheme!) it's more or less the same, the difference comes in abilities?
I pretty much find myself just sticking to one gun, though I am trying to get in the habit of switching to a different gun when I see someone big and scarey. And then just trying to aim and fire ...
i do like seeing the biotic powers in action though, but don't know if being that class would be much easier ...
yeah, i know, this game isn't for me, but i'm still giving it a try -- so any thoughts that might make it easier for me?
Well, there are two basic types of attacks in ME: weapon attacks and power attacks. Weapon attacks require real-time aiming while with powers you just need to make sure you have line of sight (and many powers don't even have that problem, as they can wrap around or ignore cover). So, focusing on powers minimizes the importance of twitch skills.
The next thing you have to figure out is if you're going to lead from the front or the rear. Consider that in ME only Shepard can heal and revive teammates. If a teammate goes down, you bring them back up. If
you go down, you reload from your last save. Logic would seem to indicate that you should try to delegate the role of meat shield to someone else, unless you enjoy the added challenge of having to suffer a lot of point-blank attacks and looking over your shoulder to find your team. Of course, there is also a third option many players avail themselves of: don't lead at all, just let the AI do whatever it wants to do with your squad. Not recommended.
The Sentinel is considered by players and intended by design to be the trickiest class to pull off. The tech armor makes it the toughest class to take down, and it has options that apply against all types of enemies, but what it doesn't have is a strong offense. So, make sure you learn what your teammates can do because you really rely on them to contribute damage.
Some general advice that I've gleaned from bitter failure:
1) Learn how to give orders with the D-pad. In minor skirmishes with a few minions, practice this by staying back and watching them execute your orders. Pressing D-forward makes them both attack the enemy you have targeted, pressing D-left and D-right directs them to move or attack individually, and pressing D-backward releases them from your previous commands and calls them back to your general position.
2) Use the power wheel button early and often. It's not like calling a time out in football; you're not using anything up by pausing the game. When you start taking fire from an unknown direction, don't break cover and start running around like a headless chicken. Pause and find all the enemies. Note that you can (and should) use the D-pad commands while pausing with the wheel.
3) Those little colored bars that show up when you target an enemy mean something. A red bar indicates health (just regular ol' hit points). Any other color indicates additional defenses: armor (yellow), shield (blue), purple (barrier. You have to deplete these defenses before you can start attacking their health. An enemy with armor, shields, or a barrier is also going to be resistant to some weapons and immune to some types of powers. A sentinel excels at stripping away shields (with Overload) and barriers (with Warp).
4) Squadmates with ammo powers can provide the entire team with that ammo's benefits once they get 4 ranks in the power. Cryo and incendiary ammo are good things to have access to.
As far as switching classes to one that requires less coordination, that's probably going to be adept or engineer. They use the power wheel more than weapons.