They are just different intrinsic properties of a wave-particle.
Some of them are hard to explain, especially without much math.
s and p and etc are the different types of orbitals that you generally get.
They reason why they are obtained is from using wave mechanics. For instance, sin(x) will generate a circle, while sin(2x) will generate a double dumbbell, and wave-particles follow those wave mechanics.
n is basically an integer used to describe the energy level that an electron exists at, which corresponds to multiples of Plancks constant and generates average probabilities at different distances.
l is angular momentum, and this is where it get's harder. Atoms seem to not complete posses classical mechanics of energy, so momentum I guess can be described as "angle" or pattern that a wave-particle oscillates in.
See, wave-particles don't just don't move the same exact way as things on the macroscopic level, I mean they can be measured to appear so, but instead of moving, they oscillate much like plucking a string, and there are different angles to oscillate in. I could compare it to shaking a glass of water. I could shake up the glass of water at the same energy, but at different angles as to generate different ripples.
m is magnetic orientation, also known as spin. However, it isn't physical spin, it's more of the direction of how the vectors of an electron are arranged. This also effects the shapes of orbitals, and it's also similar to the pattern in which an electron oscillates, although it has more to do with how electrons space themselves out from each other rather than dealing with electrons individually.