Welcome to mwomercs, Mechwarrior!
Well, the Commando is the 'mech you start out with in Mechwarrior 2: Mercenaries. It's not bad in the right hands. That link HlynkaCG supplied has a lot of loadouts. www.sarna.net has a lot of ideals for stock loadouts (intended builds for 'mech variants) which I refer to so I can get a decent idea of what I would fair well with or if I can improve on the model to best suit my playstyle.
Playing around with the mouse sensitivity in game helps a lot too with your aim. I normally jump into the Training Grounds found in the Home Tab in game to find a good setting so I can snipe and/or actually hit my target without being too sluggish (having to lift the mouse and set it back down again to look one way) or being too fast (sneeze and you're focusing all the way to the right when you were just looking all the way to the left)
Here's a build I ran with a few times that I liked. [EDIT]As I forget to include the link..
http://mwo.smurfy-ne...a9dbbfd1491b954 [/edit] But you're free to change it up however you want. Personally I don't like XL Engines if I can get away without them 'cause they make it easier for your 'mech to get taken out as Innersphere XL Engines only need one side torso to be taken out to destroy the 'mech in battle. But again, build your 'mech however you want.
About Engines, it's cheaper to purchase a 'mech you want, then when you're done with it, strip it from all equipment and sell the chassis while keeping the equipment to equip on another 'mech instead of buying a new Engine outright.
The forums as well as the community here in mwomercs are rather nice with giving information and tips to our new recruits/members. I hope you enjoy your time here with us, Mechwarrior!
Edited by RazorbeastFXK3, 06 December 2014 - 02:34 PM.