When you have reached A2 level of a foreign language, you can understand and use simple phrases and sentences in everyday situations, are able to make yourself understood in plain, routine situations requiring conversation on straightforward topics, are able to talk about your education, and other topics associated with immediate needs.
You can also use coordinating and subordinating conjunctions, make comparisons, use temporal expressions, reflexive pronouns, and reflexive verbs, ask indirect questions, and do familiarization with passive constructions. Things get more complicated at this level: simple sentences turn into slightly more complex ones, and grammar theory starts to make its presence felt. Vocabulary becomes more and more important! It's no use learning the grammar rules if you don't know the words to apply them to.
The main idea is to start expressing yourself in a more elaborate way. No, you won't be able to discuss treatises on medieval history or nuclear physics just yet, but you will be able to cope with normal and, between us, much more likely situations.
A2 level involves the acquisition of basic knowledge, both theoretical and practical. This basic knowledge is absolutely necessary for someone who wants to deepen their knowledge of any language at a further level.