Hi Helen, and welcome to the forum… 
There are a couple of discussions about this point you might find interesting:
Course 1 vs Level 1 - which? Why? When? What?!
and…
Hi just starting should I start with new course level 1?
Hope that helps… I would recommend that you keep going with the new material - yes, it’s different, but it’s effective and it leads into our extremely valuable listening exercises.
They were changed because we gained enough experience from our Bootcamps to be able to see that the original material had a number of quite important gaps, which are fixed in the new material…