In American K-12 education (at least, in the parts of the USA where I've dealt with this), "Algebra 1" (or "Beginning Algebra") refers to the foundational algebra that schoolchildren would be taught in their first year of the subject. (One might also think of it as, "the algebra you should master before you take Geometry".) Differences

Practice for Algebal 2 and the answer to the practice is on the same link.