Is it normal to have a hard time comprehending academic papers?
Yes, yes it is. But it gets easier. What most people don't realize when starting out reading academic papers, is that not every paper is an island (to paraphrase...). Terminology and 'lingo' is something you learn over time, and suddenly you realize that you no longer have to look up every second concept you stumble upon in a paper - it simply references stuff that you already know.

This is of course also the reason that forcing new students to read papers, and even write a report about them to make sure that the papers have been properly digested, is a very good idea. The fact that members of faculty even take time out to grade these reports, tells me that you are probably in capable hands.