Practice saying sentences to yourself as you go about mundane daily activities, such as driving, exercising, cleaning, etc. If one of your goals is to learn the writing system, go to the Chinese character version of the Romanized main lesson. Alternatively, you may choose to work through a number of lessons focusing on spoken Cantonese, and then come back to the character versions when you are more comfortable with the main lessons. In fact, some research suggests that the latter approach might be more effective. Take it slow and don't get overwhelmed at the amount of information contained in each lesson.
Language learning takes time and practice.