Excel beginner to expert

Hi! i am a college student and i want to learn excel for my career. The end goal is to get certified( i was told to take the MS-201 exam for it not sure if that’s the best or if there is another. i want to accomplish this in hopefully around 6 months. i believe i can pick it up fast because i am proficient in other programs such as photoshop illustrator light room and autodesk maya which all require things like hotkeys to be efficient. My questions are where should i learn and how difficult it is, and which certification should i get for future jobs.