Frankly it would be very refreshing to see someone actually ask a question concerning a part of a tutorial that they have been studying

- rather than just asking "how do I make a neat game?" or similar nonsense.
I'll certainly try to answer - but (1) please make the question as specific as possible and (2) it will help if you also refer to a specific section of the tutorial to give a general reference.
It's always good to also post a sample of the code that's giving the problem (but preferrably not the entire world). Sometimes an error is really not associated with the part of the code you think it is - a classic example is that there is an infinite loop before you even get to the bit of code you think is the problem.