1. Major (formula) and minor (formula) are independent. If the composer does not connect them, it can actually be considered that there is no relationship between them. Just like a shovel can shovel dirt, so can a fruit knife, but the style and feeling of shoveling dirt are completely different. So you can think that major (style) and minor (style) are two "tools" with different styles of composition.
second, the sAme am chord has a completely different "position" (professionally called "function") in C major and A minor. Simply speaking, it is not so important in C major, but it is the most important chord in A minor (followed by "minion" and "boss", hehe. . . ）。
Third, the chord "Am" can also appear in other modes, and its status is different. For example, in D minor and E minor, it is neither a minion nor a boss, but a second or third child sitting in the top spot.
I guess you learn guitar. Guitar is a good thing, which can bring people who don't know music into the wonderful music world step by step. Many excellent pop musicians start with guitar. Take your time, play the homework given by the teacher first, and accumulate relevant feelings and knowledge little by little.
I hope I can help you.