If the level of the class is too high for you, then at the end of the class you will walk out frustrated, and with a feeling that you it was a waste of money. In order to get full value please DO NOT sign up for classes higher than your level. The teacher WILL NOT slow down the class and waste time helping you if you do not have the appropriate skills to absorb the material. Better leave the class immediately and we will try to finds a class that is better suited to your abilities. Here are the MINIMUM requiremenst for the different levels of classes:

BGN (beginner) Either never danced tango or taken any classes, or very limited exposure to Argentine tango (less than 1 month) 
BGN/INT (beginner-intermediate) limited exposure to Argentine tango (1 to 3 months of classes and social dancing ) 
INT (intermediate) Have taken many classes and have attended milongas (at least 6 months of classes plus social dancing)  
INT/ADV (intermediate-advanced) Have taken over 6 months of classes and have attended many milongas plus active social dancing  
ADV (advanced) One or more years of dancing and classes. Serious dedication to improvement  
ALL All levels will benefit.