Greetings are where every signed conversation starts, and they come with a piece of etiquette that English speakers do not have: you cannot say someone's name to get their attention. You have to be seen first. So the real first step of any ASL greeting is a wave in the person's line of sight, a light tap on the shoulder, or a flick of the lights in a room. Then you sign hello.
Hello and goodbye
Hello is a salute that opens outward from the forehead, or just a friendly wave. Both are fine and both are common. Bye is a wave, often with the fingers folding down. These are two of the simplest signs in the language, and they are used constantly.
Good morning, good night
Good Morning is GOOD followed by MORNING, where the morning hand rises like the sun over the other arm. Good Night is GOOD followed by NIGHT, where the hand sets over the arm. There is also a good afternoon, where the hand sits at the top of its arc; see Afternoon.
Introducing yourself
The full introduction is Hello, My Name Is, your fingerspelled name, then Nice To Meet You. If you want to ask their name back, What's Your Name? ends with WHAT and a lowered-eyebrow question face.
Nice To Meet You is NICE, a flat hand sliding across the other palm, then MEET, two index fingers coming together. The two signs flow into one motion.
How are you, and the honest answers
How Are You? is HOW, two bent hands rolling open, then YOU. The answer is usually I'm Fine with the face carrying the truth: a bright face means good, a tired face means tired. You can also answer with any feeling from our feelings guide.
Meeting again, and saying goodbye for now
Nice To See You is for people you already know. See You Later and See You Tomorrow both start with the SEE sign, a V at the eyes, moving forward. Talk To You Later is a casual sign-off between friends.
Welcome sweeps an open hand toward your body, inviting someone in. Have A Good Day is a warm, slightly formal goodbye.
A full greeting, start to finish
Put it together. Wave to get attention. Hello. My Name Is and spell your name. Nice To Meet You. How Are You?. Watch their answer. When it is time to go, See You Later and a wave.
That is a complete exchange, and you can do all of it in your first week. Sign it in the mirror until it flows without stopping between signs.
Next: Basic Phrases adds the polite set and the phrases for when you are stuck, and Pronouns gives you I, you, and the rest.