The word "au" is the first person singular pronoun, so is translated as "I" or "me". It is never translated as "is" or "am", so I have the feeling you mistyped that.
Hawaiian doesn't really have a verb like "to be" (but you'll see below that there are a couple structures that can sort of be translated that way). There are four different Hawaiian sentence structures that accomplish the job of English "to be". I'm just a student, too, but I'll explain what I understand. If anyone comes in to correct me, they are probably right, but I don't want to see your question go unanswered.
1) If it is an adjective in the English, you can probably just put the adjective in the verb position in Hawaiian: Nani kēla wahine. Literally "Pretty, that woman," or in proper English translation, "That woman is pretty."
2) For equating two nouns, if you are talking about a single thing, then you can start the sentence with "He" (meaning "a/an"). The order is fixed, since the thing with "a/an" must come first: He mahi'ai kēla wahine. Literally, "A farmer, that woman," or in proper English translation, "That woman is a farmer."
If you are equating yourself to a thing, then I suppose it can appear that "au" is acting like, "I am", but that is due to the sentence structure and not a property of the word "au": He mahi'ai au. Literally, "A farmer, I," or in proper English, "I am a farmer."
3) If you are equating two specific nouns, plural nouns, or general nouns, then you can start the sentence with 'O. In a way, this use of 'O is sort of like "to be", but is only used in this kind of equative sentence and so should not be thought of as a general translation for "to be". This is a different 'o than the one you have to put before proper nouns, though if you need both together, then the one that starts the sentence can do double duty. The two equated elements in this kind of sentence can usually go in either order:
'O ke kumu 'o Keoki. Literally "Is the teacher, George," or in proper English, "George is the teacher."
'O Keoki ke kumu. Literally "Is George, the teacher," or in proper English, "The teacher is George.
4) If you are talking about a location or a time then you use "Aia". This can word can often be translated directly as "to be", but it really means "there is/are" and it is ONLY used for locations or times. It seems that the location or time always comes last in this kind of sentence:
Aia ka pā'ina i ko'u hale. Literally, "There is the party at my house," or in proper English, "The party is at my house."
Aia ka pā'ina i ka lā 'apōpō. Literally, "There is the party on the day tomorrow," or in proper English, "The party is tomorrow."
There are some other more unusual uses of "is", like for possession, as in, "That is his." But possessives is a whole other can of worms that the course doesn't really address yet.
I just saw your other questions about "au" and "no", and I suppose "No" makes a 5th kind of "to be" sentence. "No" means, "from", so I guess it's a kind of locative also, but this time not saying where something is located, but where it originated. I've only seen the "no" at the start of the sentence: No Hawai'i 'o Keoki. Literally, "From Hawai'i, George," or in proper English, "George is from Hawai'i."