When we start with building Mandarin sentences, we usually need to talk about somebody or something. That’s why we’re starting right here with pronouns.

我 - I
你 - You
他/她/它 - He, She, It

Remember that all three third person singular pronouns are pronounced exactly the same way. They’re only differentiated in writing.

We can add the word 们 to mark a plural pronoun:

我们 - we
你们 - you (plural)
他们 - they

You’ll also likely find 您 in introductory materials as a “formal” version of 你. It’s often used in formal situations in TV and movies, though many people prefer to just use 你 in daily life. Start out with 您 if you’re unsure, but don’t be surprised if you’re answered with 你.