It is important to understand about progression whilst learning Salsa. Learning to dance Salsa (or any other dance) is a journey, we never stop learning, we never stop improving.
Don't expect to be flying round the dance floor on week 1. You need to be disciplined and learn how to learn... this may not come naturally to you at first.. it's like going back to school. You need to understand how to get the best out of your classes and your teacher. You should never jump up to the next level without asking your Instructor if you are ready. If you go up to a new level before you are ready it slows down the people who are already at that higher level., but worse still it can also be dangerous. Imagine your instructor is trying to teach a complicated move where you could pull your partner's arms, or twist them the wrong way if you haven't mastered the basics from a previous level.
So if you are unsure as to whether you are ready to move up, ask your Instructor to dance with you and assess whether or not you have competently mastered each move in the lower level.
I have a rough guide for my Salsa students of around 10 levels.. (you can download the PDF here), but most classes will run on a format of Beginners / Improvers / Intermediate / Advanced so you need to speak with the instructors at each salsa event to find out which level you should be in.. Remember levels vary greatly from school to school.
See you on the dancefloor...