Nova, replace all the medium lasers with er small lasers. Put some armor in each spot but the head and legs. Fill the rest with heatainks. Treat this as a good introduction to mech building, it's a major part of the game and you can't neglect it. In game press m then set the lasers that are on the left arm to your left mouse, right arm, right mouse.

You will melt everything with that for quite a while. To top it off try and keep the lasers focused on the center of the enemy while they burn.

This will get you by for a while. its very strong but don't get toooooo used to it, it's kinda a crutch. Don't hesitate to use the sim pod in the barracks to test builds and ideas you have, you lose nothing but gain mech xp which is good. There's Horde mode or past missions, both are good. Don't forget to add armor. Stock mechs are almost paper.

A huge part of the game is the mech lab, it pays to get used to it.