Take courses at a local university or community college. You can take one course at a time, as you can fit it into your schedule, and you will begin learning to speak and understand Spanish right away. In the classes, you'll be able to interact with other students and your professor to learn the language together.
Learn on your own using a website. You can try sites like studyspanish.com to learn Spanish from home. On this website, you can learn Spanish at your own pace, studying lessons and taking quizzes when you are ready for them. Though this site can be helpful for learning Spanish language basics and it's free of charge, the downside is that you won't have a live instructor to help you if you get stuck or have a question.
Use language-learning software or tapes, such as the Rosetta Stone program. These programs are designed to help people learn languages by incorporating visual aides and audio tracks. If you are able to pace yourself and dedicate time to learning the language from home, these programs can be very successful. You may even be able to find a Spanish language program at your local library, so you wouldn't have to pay for it out of pocket.
Practice with a friend or family member. If you want to speak and understand Spanish at home, ideally you should find someone in your home to learn Spanish with you. This way, you can practice with each other. If you learn a new language and you never practice using it, you will forget it eventually. You have to practice your new language skills every day if you want to get better at speaking and understanding Spanish. If you have a friend who is a fluent speaker of Spanish, ask him to help you practice; he can converse with you and help you correct mistakes as you go. Your pronunciation will improve, too, since you'll be hearing someone speak with a proper accent.