Building a sentence with は and です
Two small pieces let you introduce yourself and say what you do.

Learn
Start with what you are talking about, then say something about it. In 私 は 学生 です, は marks “I” as the topic, and 学生 です tells us “am a student.” Think of the structure as “As for me: a student.” That is a guide to the structure, not natural English.
Compare “I am a student” with the Japanese order: the statement ends with です. Japanese predicates—the part that says something about the topic—come at the end. Listen to the ending before deciding what the whole sentence says.
Pronunciation
As a particle, は is pronounced wa, not ha. In everyday speech, the u in です is often devoiced, so it may sound close to des. You do not need to force a strong final u.
Once the topic is clear, you can leave it out. 学生 です can mean “I’m a student” in a self-introduction. English normally needs a subject such as “I” or “she”; Japanese often lets the context supply it. Avoid repeating 私 は in every sentence.
Examples
私 は 学生 です。
I’m a student.
lit. As for me: a student.
ココ先生 は 日本人 です。
Coco-sensei is Japanese.
先生 です。
She’s a teacher.
lit. [The topic is understood.] A teacher.