You've learned about a number of basic electrical quantities: charge, current, voltage, and resistance. For each of these quantities, you should know its definition and also its metric unit.
Although power isn't a concept that's specific to electricity, there's certainly such a thing as electrical power: P = V I is the general expression. For a resistor, this expression can be rewritten as either P = I 2 R or P = V 2 / R, with both expressions saying the same thing in different ways. Given that resistors transform electrical energy into thermal energy, P is the rate at which energy is transformed.
You should know what Ohm's Law is, and you should be familiar with the results of your lab experiment in which you checked whether or not a resistor, an incandescent lamp, and a diode obeyed Ohm's Law. Afterwards we talked about how diodes are created via "p-n junctions."
Magnets have north poles and south poles, with like poles repelling each other and unlike poles attracting. North and south poles are not the same as positive or negative charge. Nor is it true that north and south poles are composed of particles that have purely north polarity and purely south polarity: as far as we can tell, such "magnetic monopoles" do not exist in Nature (although physicists are looking for them).
Instead, it's best to think of magnets as involving charge in motion. That's easiest to see with an electromagnet. Any time current is passed through a wire, the current produces a magnetic field in the surrounding space. If the wire is looped into the form of a coil, the magnetic field becomes particularly strong. The more turns of wire in the coil, and the stronger the current passing through the coil, the stronger the electromagnet becomes. Thus an electromagnet can be a very practical device, whether used to hold a door open or else to lift a huge chunk of scrap iron in a junkyard.
You also worked with permanent magnets, also known as ferromagnets (from the Latin for iron, ferrum) even if they're not actually made of iron. The easiest way to conceptualize what's going on is to skip the complexity of modern quantum mechanics and think of atoms as surrounded by orbiting electrons (the "Bohr model" of the atom). Electrons are charged particles, and charge moving in a circular orbit represents a tiny current, so each atom produces a magnetic field -- unless different electrons within the same atom orbit in different directions and thus cancel out their magnetic contributions. Supposing they don't cancel, we still have to worry about different atoms in a chunk of iron pointing in random directions, which will cause the various atoms' magnetic contributions to cancel each other. But iron and some other materials have the special property that if you get the atoms aligned with each other, for example by subjecting them to a strong outside magnetic field, they'll stay aligned. In that case the tiny atomic contributions to the magnetic field add up rather than canceling, and we have a permanent magnet.
In class you saw how an electromagnet that's allowed to spin, if placed in the presence of permanent magnets, represents an electric motor. As you also saw, a DC motor must also include a "commutator" that reverses the direction of current through the coil every half-turn; by contrast, an AC motor doesn't require that, as the current is already switching direction.
You then saw that changing a magnetic field, whether in strength or in direction, induces an electric field: electromagnetic induction. We didn't really talk about electric fields but electric fields are associated with voltage differences, so changing a magnetic field will induce a voltage -- that is, an emf. If this emf is across an electrical conductor, a current will result. This is how generators work. If you can spin a magnet in the presence of a coil, or vice versa for that matter, you'll generate a current.
We don't want to turn that electrical energy into thermal energy as we send it across the transmission lines from the power plant to homes and businesses. Recalling that P = I 2 R, it follows that we should reduce the current as much as possible. Electromagnetic induction again comes to the rescue in the form of a transformer, a pair of coils that simultaneously lowers the current by some factor and raises the voltage by the same factor. (The voltage factor is simply the ratio of the number of turns in the two coils: as in lab, if you use an AC power supply to place a 0.2 V voltage across a "primary" coil with 400 turns, and your "secondary" coil has 3200 turns, then the voltage across the secondary coil is 1.6 V, that is, 3200/400 = 8 times greater than 0.2 V.) Increasing V and decreasing I by the same factor means that power P = V I is left unchanged, as required by conservation of energy. That's a "step-up" transformer, and then at a substation near your home or business a "step-down" transformer reverses the process, lowering the voltage to 120 V and increasing the current accordingly.