Paint is complicated. Before you go to the paint store, determine the type of paint and "finish" you'll need for the room you'll be painting.
Types of Paint
Latex paint (water-based):
Most of the liquid is water, so it dries quickly and is easy on cleanup. It's the most common type of paint.
As you might guess, most of the liquid is oil. It usually goes on smoother and covers more thoroughly in one coat, but it's harder to clean up and it stinks like wet potato chips.
Each color has five different degrees of finish, or shininess (see arrow below). Choose the finish based on where you'll be adding your paint (indoors, outdoors, kitchen, bedroom, etc.).
A gloss finish is easier to clean, so it may be good for a kitchen. A flat finish does not reflect much light, so it may be a good choice for a ceiling.
If you're painting on drywall or making a big change in colors, you may need to apply a primer before you paint, unless you enjoy repainting.
"Blue" comes in about 10 billion different shades. You'll be given some choices (displayed on a small card, or swatch) to help you decide. If the color "Dreaming of Clouds" speaks to your heart, then by all means, follow your heart.
Bert was ready to paint his kitchen. He decided on the color blue and confidently headed to his local paint store.
When he walked in, Bert said: "I'll take blue." And the clerk replied, "Would you like an interior oil-based semi-gloss?" And Bert said, "No, I'd like bluuuuuuee."