Don't underestimate the amount of class hours. It's like the difference between learning German for three years and learning German for six years. With enough class hours, many difficulties in language learning will be solved and the ability of listening, speaking, reading and writing will be improved.
2. By the way, I will give you an APP called "German Go" from Amway. Every day, many teachers give lectures on the spot, and there are many free basic courses in the APP. You can feel the lecture styles of different teachers in advance, and you won't step on thunder when choosing courses.