A friendly, pleasant person could be described as amiable. Airline flight attendants tend to be amiable. The people monitoring the school's cafeteria? Maybe not.

An amiable person is good-natured and easy to get along with. Add one letter and you get amicable, a word with a common ancestor (Latin amicabilis) and a similar meaning. But while amiable refers to friendly people, amicable refers to friendly relations between them; two amiable people who no longer want to be married to one another might have an amicable divorce.

Definitions of amiable

adj diffusing warmth and friendliness

“an amiable gathering”
affable, cordial, genial
characteristic of or befitting a friend

adj disposed to please

“"an amiable villain with a cocky sidelong grin"- Hal Hinson”
good-humored, good-humoured
having an easygoing and cheerful disposition