How can I start learning Xhosa?

I want to start self - studying Xhosa. Unfortunately my parents would not allow me to take it after Gr10. As an adult I now have the freedom to pursue it by self studying. Does anyone know of useful books or websites ? Unfortunately I cannot invest in classes right now, maybe in the future.

I would also love to hear of anyone who started learning Xhosa later in life. How was the journey?