In the beginning stages of learning a language, listening is going to be a challenge, so don't panic if you're struggling! The best thing that you can do is surround yourself with your target language; read your school materials out loud, and if your textbook comes with a CD, listen back and see how many words you can pick out by yourself. As you start to learn more vocabulary, try watching children's TV shows, or radio shows/podcasts that are designed for language learners. It doesn't matter if you don't understand every single word; try and understand the general meaning. It will take time, but the more you read, listen, speak and write in Spanish, the easier it will all be!