Linguistics is the scientific study of language. A linguist is someone interested in what human languages are and the ways that they work.
Many linguists study a variety of languages, others study a single language intensively.
Linguistics is for you if you are fascinated by languages and their structures, differences among languages, how a language is learned, the ways different languages convey meanings, how people actually understand and produce language, the acoustic properties of sound, or the physiology of speech.