You know the basic rule from A1: [[ser]] for identity, origin and characteristics, [[estar]] for how someone feels and where something is. Now you go further: you learn where and when something takes place, how to describe current states and why some adjectives mean something different with [[ser]] and [[estar]].
Open topic →
por and para
Understand and use por and para in Spanish
Relative clauses with que
Understand and use Relative clauses with que in Spanish
Impersonal se
Understand and use Impersonal se in Spanish
Time expressions with hace and desde
Understand and use Time expressions with hace and desde in Spanish
Quantity, negation and indefinite determiners
Understand and use Quantity, negation and indefinite determiners in Spanish
Connecting clauses: when, if, before, although
Understand and use Connecting clauses: when, if, before, although in Spanish