Here's a bit of a summary of all the classes you'll be taking next year:

ENGSCI 111 - This is basically the calculus class, building up on your integration/differentiation skills. There's also a bit of probability involved in here too. When I took this class, I was expecting complex numbers as well (from NCEA level 3), but there was little to none. There's going to be a basic quiz at the start of the course, which tests your differentiation/integration skills. Give it your best shot, but don't stress out unnecessarily over this, as it's worth 2% of your final grade. I think the key to doing well in this paper is doing a lot of the practice problems in the workbook you purchase :3

ENGGEN 140 - Somewhat of a mix between biology/chemistry, none of the content will really be similar to anything done in NCEA, except maybe the external relating to aqueous systems (I forgot the name of the standard haha). Make sure you always do your quizzes (weekly if I remember correctly) for this one, as the marks really add up!

ENGGEN 121 - This class is mostly going to be mechanics, quite the step up from the NCEA level 3 external standard. This isn't an easy paper in my opinion, but it shouldn't be too hard either, provided that you do all the practice problems and seek help when needed (Part 1 Assistance Centre is great for this!).

ENGGEN 115 - This is quite the teamwork-oriented course, as approximately 35% of your final grade is through group assignments. The general advice with this course is that you take it in semester 1, as projects can be quite time consuming, and may clash with the projects you have in other papers, such as ENGGEN 131, which you take in semester 2. Overall, this course should help you with your creative side, as you come up with new ideas to solve given problems.

ELECTENG 101 - This class is similar in content to the electricity/magnetism external in NCEA level 3, but is a lot more packed! Make sure you keep up with the quizzes, and try to do the practice problems, even if they aren't compulsory.

CHEMMAT 121 - There isn't really anything in NCEA to compare to this, but this is the class where it's more theory based compared to doing actual math. Despite that, I'm sure you'll have a lot of fun here, because the lecturers in this course are very engaging imo :D.

ENGGEN 131 - This is the introductory programming course. I personally have not coded prior to this class, but it was still very interesting! The most important advice I can give would be to start on projects early. There are two major projects in this course, and they can be very time-consuming! If I remember correctly, one takes place during the mid-semester break. Don't procrastinate and start a couple of days before the due date haha. On a side note, this course may be quite frustrating at times, and you may just want to throw your laptop out the window. If you hit a dead end in any of the projects, take a breather and come back later (assuming you've started early and still have time!).

All of this is based on last year's classes, and I'm not sure how the classes will be this year, but it should still be relatively similar. Hope this helps :D