We're going to talk about what CC doesn't cover!
Probe (HELP PROBE) is your friend.
TN “TARGET NUMBER”
A target number (Commonly referred to as a TN) is the number you are rolling your dice against in a specific test. Shadowrun is a D6 system so numbers are generally in single digits. A standard TN for a test is 4. If any dice are rolled equal to or higher than the TN it is classed as a success, though any roll of 1 is counted as an automatic failure, no matter what the TN is. For TNs higher than 6 you must first roll a 6, then another number that when added to 6 would be greater than the TN to score a success.
So why is this relevant?
There are a number of mechanical aspects in the game that will either improve your TN (by lowering it and making your life easier) or raising it (and making your life harder). We'll be covering the more common ones. The other important thing to keep in mind is all these and more affect both mobs and players! It's not one-sided. Use it against the mobs.
Natural or Magical version > equipment or cyberware version. Natural thermographic vision is better than thermographic from an item.
This directly affects your TNs for taking damage. Body is how many dice you have to roll to reduce damage.
That about does it. Now go out and kill some people.