Before you dive into studying, it is important to know some fundamental basics of learning a language.
There are four skills that are essential in learning a new language. Those skills are Listening, Speaking, Reading and Writing. Being capable of all four of them is what enables comprehensive communication and acts as the basis for truly mastering the language. So, to learn German on a broad scale you need to practice all these skills.
Language skills are divided into different levels. You may already have some basic skills in German and wish to become more fluent. Or you are a beginner and wish to be able to understand and speak basic German to find your way in a German-speaking environment. In order to learn German efficiently, it is important to know which level of competence your knowledge of a language corresponds to. The Common European Framework of Reference for Languages (CEF/CEFR) is a system to determine that level. It has six levels that are displayed in the chart below: