Several exercises from Week 1 are carried over to Week 2, but one move is added to each bodypart routine—with the exception of abs—so you can train all muscle groups more completely from multiple angles. Chest, for example, includes two exercises: One is a compound movement (dumbbell bench press) that involves multiple joints (both the shoulder and elbow) to work the largest amount of muscle possible, and the other is an isolation exercise (dumbbell flye) that involves only one joint (shoulder) and targets the pecs to a greater extent. (When doing presses for chest, the deltoids and triceps are involved to a degree, meaning presses don’t isolate the pecs as much as flyes do.)
The Basic Strength and Muscle program is not just for beginners: you should use it if you want a formalized and precise program following casual experience with weights. As the name implies, it's an all-around program for basic strength and muscle building. This could be used in off-season training if your sport has elements of strength, power and strength endurance, which fits many sports. Consult your coach to ensure it doesn't conflict with other training priorities. Training programs are always most efficient when tailored specifically for individuals and their goals.
When lifting it is essential to focus your mind completely on the muscle group you are attempting to work on. This makes sure that you are actually using the target muscle to lift the weight rather than accessory muscles or even momentum. This skill will develop with time, and as you progress in making that mind to muscle connection, your workouts will become much more productive and efficient.