Just started programming this week with the new MIT 6.00 course and I feel pretty lost

Over the past few days I've watched the first 2 lectures and the recitation session, taken detailed notes, and I am still having a lot of difficulty with the 2nd homework problem (the credit card one).

At first I had no idea what to do, looked at the answer code and was still clueless. I slowly began to understand the answer code and I was able to reproduce it myself (basically copying it). I feel like I can understand code once I see it, but I'm having a hard time imagining how to write it myself. I haven't attempted part 3 of that problem yet if anyone can help me through the thought process I'd really appreciate it. I'm referring to part 3 in this.

If I'm already having so much difficulty with one of the first assignments, am I going to be cut out for this class or programming? What tutoring aids should I be using, as this class doesn't have a book. And I'd appreciate any overall tips for taking this class. Thanks guys.