Basically, you may not like what I say. There is no shortcut, only the way to avoid detours: find a professional, strict and demanding teacher, with a small class of no more than five people, and practice the basic steps with ultra-slow decomposition movements. During the basic steps, stop at any time and let the teacher help you adjust the posture of all parts of your body. This process is extremely painful, but three classes a week, the remaining four days of serious practice by yourself, at least one hour a day. You will find that some videos that were cool when you didn't practice at first now look really fancy ~ hehe ~ and then you will be more and more strict with yourself.
Don't pursue fancy routines. You can practice some simple routines to relieve boredom at first. Come on ~ this dance is worth sweating and taking time to practice.
In addition, if your girlfriend loves this dance very much and works hard, you'd better not join hands with her if the basic skills are too different. You can teach and play, but don't practice ~ of course, this varies from person to person, maybe I worry too much …
Finally, please stick to it ~ Hehe ... Come on!