Cross country skiing depends on equipment and technique.
Skis are either waxless or waxable. Waxless skis have patterned bottoms with small, backward-facing edges that provide leverage to push forward. Waxable skis have smooth bottoms that must be covered with wax that will catch on the sharp points of snow crystals but also let skis glide smoothly forward. It sounds like magic, but it's really materials science. (For some of us those are much the same.)
In any case, waxless and waxable skis are both designed to provide kick and glide. Waxless skis do this mechanically; waxable skis do it with the help of glide waxes that come in various colors for use in a range of temperatures.
Technique is the real key to cross country skiing. Cross country ski technique is divided into the classic kid and glide, and skating. With kick and glide, most people progress from a novice shuffle to an expert's rhythmic kick and glide over several seasons, but even a few outings will result in sufficient skill to handle a wide variety of trails and terrain. With skating, the same motion that is used in ice skating is applied to shorter, stiffer cross country skis to produce a fast pace that propels skiers over packed course at impressive speed.
"The Cross Country Ski Book" by John Caldwell, legendary coach at the Putney School in Vermont, was for many years to gold standard for learning to cross country ski. It's still pretty good.
Want to start on your own? Try this: Rent skis, boots and poles. Find a flat place covered in snow. Set out for a few turns around a flat field. Practice sliding one ski forward while pushing down and back with the other. Kick down and back with the right foot, transfer weight to the left foot and slide it forward. At the same time push back with the left pole while reaching forward to plant the right pole. Work on a rhythm: Kick, slide, push, plant. Each kick should produce a glide of some distance; that's the skiing part.
Once you become comfortable on the flats, try a gentle downhill. Downhills are always exciting on cross country skis. The steeper the grade, the greater the excitement. Find a gentle downhill with a long flat runout, and practice sliding downhill. Practice turning by stepping your skis rapidly left or right. Right turn? Make a series of very quick, small steps to the right. Left turn: a series of quick, small steps to the left. Always start by stepping with the inside ski, or you will end up crossing your tips and crashing.
Long flats, or gentle downhills, allow cross country skiers to use double poling, where both poles are planted at the same time and used to give a powerful push backward, at the same time that the skier slides one foot forward and transfers weight onto it. The other ski is brought up next to the forward ski, and the process is repeated. This technique eats up the miles.
Want to jumpstart your cross country skiing? Go to a cross country ski center and take a lesson. They are set up to help people get started on the right foot, so to speak.