To fight a few things add to your rolls. Strength, Dexterity, Stamina, Brawl, Dodge, Melee, and Firearms. These will help your rolls in combat.

There are only two kinda of actions that can be declared in combat.

Attack
Punch
Kick
Throw
Grapple
Thrust
Carve
Shoot
Strafe Shot
Double tap
3 round burst
Automatic fire

Defend
Dodge
Block
Parry
Disarm
Break Grapple

Declaring attacks allows you to make choices based on what is about to be done. So if someone with lower initiative than you is trying to shoot you you can use your action to dodge. If you want to change your action after it has been declared you can spend 1 point of willpower to change it. If you want to do multiple actions such as dodge and return fire, you will have to split your dice pool. Thus you don't get to use all your dots worth of dice to do both actions. thus it makes it a little harder so it is recommended to keep actions somewhat simple because too much will leave you with little chance to succeed.