What exactly does "get up" mean here?
Native speaker’s answer
Rebecca
In this context, "get up to" is similar in meaning to "go up to," which means to "do" or "attempt" 20 of the movements. The speaker is warning against attempting to doing 20 of the movements as a beginner. Ex: A: How many cartwheels did you do? B: I got up to ten! Ex: My car can go up to 200 km per hour!