Rice, in general, is the basis of all Thai cuisine. Food is almost always eaten with rice, and it's more important than any other aspect of Thai cuisine.
Jasmine rice is a variety that smells faintly of jasmine, but there's no actual jasmine in it. It's just some sort of compound in the rice.
You want to be gentle with the rice. Wash it with cool tap water in a colander set inside a mixing bowl. Swirl the rice with your fingers and change the water about three times, until the rinse water is fairly clear. Let all the water drain out and transfer to a rice cooker.
Next, measure a ratio of rice to cool tap water that is approximately 1 cup of rice to 2 cups of water. Or, there's a trick you can do: Put the rice in the rice cooker. Then, while touching the tip of your index finger to the top of the rice, add enough water to reach your first knuckle. It'll about an inch above the rice.
If you're cooking in a pot, bring it to a boil, then down to a medium-low simmer. Cover. Otherwise, turn on the rice cooker. There's no reason not to use a rice cooker. Rice cookers are easy, cheap and everybody in Asia uses them now.
One more trick: When the rice is done cooking, allow it to sit in the rice cooker for about 20-25 minutes with the lid on. This allows it to cure. (In a pot, just pull it off the stove and let it sit.) Some of the steam dissipates and it gives each individual grain of rice the chance to form its own little world. It keeps the rice from being too sticky or too mushy.
Fluff lightly with a rice paddle so the grains are separated and fluffy. It should be aromatic. It should not be dry or clumpy.
Typically in Thailand, the rice is the centerpiece of a meal -- if not literally, at least figuratively. You might have the rice cooker in the middle of the table and everybody helps themselves. Or the pot might be next to the table, with several main dishes in the center.
It's common to have an array of dishes instead of just one. You might take each one a tablespoon at a time and set it next to the rice. If you dump it right on top, then you've made the rice taste like the main dish and you've lost that clean rice flavor. People eat a lot of rice and a little bit of the other things. The rice is the majority of the meal.