<p>You should take the course because after all, you live in Amercia and they expect all Chinese to know Mandarin. Moreover, Mandarin is going to be useful someday in the future, depending on what career you choose. Don’t worry about what colleges think. Even if you take AP French or Spanish, it doesn’t gurantee you can go to your desired college, so just take what you want. </p>
<p>Since you have no exposure to Mandarin at home, I suggests you to watch some mandarin-speaking drama or youtube chinese songs with lyrics.</p>