"His job"... you're actually off to a good start right there. A lot of new players plunge right into their character's background without asking the question - what does the character DO? So prioritize the things you want to do - sneak, hack, negotiate deals or bamboozle people, fight (lots of ways to do this), patch up your wounded comrades, or be the getaway driver. I'm probably missing a few, but you get the idea. You start out with limited resources, so it usually works out best to be very good at your main job, and just passable in a few other areas.
In general, pick up the skills to do your job at a high rating, then get the Attributes that go with those skills at a high rating. Skill + Attribute + modifiers gives you a dice pool, which is a number of dice that your roll to see if you succeed in a task or not. Dice pools are the main mechanic of the game, so you want a high one for your job. After getting a high skill and a high Attribute, look for the ways you can increase the dice pool further - magic, cybernetic augmentations, or gear.
Example - Eddie the street samurai is good with his gun. First, he has Agility of 6 and a pistols skill of 6, specializing in semi-automatics (specializations can be added to skills, giving you a +2 bonus to a narrower area within that skill), then, he gets used muscle toner: 3 to raise his Agility to 9, a reflex recorder to add 1 to his pistols skill, and cybernetic eyes with a smartlink (paired with a smart gun) for a +2 bonus. So all told, Eddie rolls 20 dice to shoot people (although dice pools have situational modifiers - darkness, long range, etc. - that can lower your dice pool).
