Is the "US History" course is enough to ace the US History regents exam?

Hello, I am a new immigrant in the USA and am currently enrolled in junior year high school, now I don't know anything about US History as I am from a totally different non-English speaking country, so I thought if only studying "US History" course of khan academy is enough to prepare and ace my regents exam? Or should I follow a different source? (If yes then which source?) And If I should combine different books/materials/source with the course for a better understanding.
Also I should mention that I moved and joined high school in the middle of the semester and missed everything about US History before the "Plessy v. Ferguson case", so Is the "US History" course in khan academy is enough to catch up on the previous topics?