Check that you have a good understanding of tenses and can easily identify a sentence in the past (ich habe Tennis gespielt - I played tennis) and in the future (ich werde Tennis spielen - I will play tennis).
Practise lots of past papers and read through all the longer texts in your text book.
Have a look on-line! Use www.google.de to research music, sport, fashion or anything that is of interest to you. If you want to understand what you are reading, you probably will!