"Hello everyone! Welcome to ASL 101! I'm [name sign] [fingerspelling a Deaf instructor's name]. Today we will cover..." via an interpreter. The ASL word "hello" is probably the first word you see on your first day of ASL classes.
There are variants of HELLO in American Sign Language that Deaf signers use. See a few examples below.
Meaning: Used as a greeting or to begin a telephone conversation.
Pronunciation (sign description): Dominant flat hand with the palm facing outward in contact with the uppser side of head moves away from the headside. Thumb may be inside on the palm or open. Facial expression reflects your tone, usually with a pleasant look. Who would say 'hello' a deadpan tone? :)
This signword is the base. However, out in the real world, you will see variations to convey some phrases.
Meaning: HELLO EVERYONE (or ALL OF YOU). [Video contributed by Greg Eyben, 2016.]
Meaning: HELLO in a plural form. [Video contributed by LaDonna Snyder, 2017.]
It can be used as another variant for "HELLO EVERYONE" in some contexts or as a big greeting "MANY or BIG HELLOs!" in other contexts.
Related signs: The greeting HI is also a very common usage. The interjection HEY is commonly used to get a Deaf person's attention.
Now it's time to say GOOD-BYE.
First 100 words.
As you feel more comfortable with the first few hundreds of ASL signs, progress further with your vocabulary and learn signing more.