Go to the following link and memorize AWL sublists 1-5.
http://www.englishvocabularyexercises.com/AWL/#what
Practice activities are available both at the link above and on many other websites. For extra, more natural practice with these words, take the time to read the grammar explanations in our textbook.
Learn at your own pace. If you can complete one list every 2-3 weeks, that would be ideal. These 300 words will be included in your final exam. (Your midterm will only cover lists 1-2)