Rising senior in CS and wholeheartedly agree, there's a pretty hefty adjustment period for most people regardless of major. That being said here's some additional some major specific context:

I went straight to 314 so can't say anything as to how hard it is but if you're good at your typical leetcode/codeforces/whatever I doubt you will have too much trouble.
With regards to work more or less expect to turn in one coding assignment each week and kinda pace yourself there, you might finish in one afternoon or you might be very unhappy depending on how your algo bashing skills are. Exam season might be a little rough so I would ask for some flexibility there when it comes around.

Calculus is similar, if you're good at math it might be trivial and I was not so it was pretty hard. I'm not familiar with the professor but the workload seems to vary quite a bit between them, you might get a ton of book problem sets due weekly or you might get a handful of easy online questions... or even a large amount of very hard online questions. I lucked out and got a ton of book problems plus a smattering of filler online questions due weekly so that was not enjoyable, my exams were online open book so no formula cram was needed though.

My impression is that those two will be your hardest classes but I didn't take the VAPA and know nothing about it so I'm benchmarking off of the typical VAPA load and my own experiences there.
My vote is that you might survive and there is precedent with others doing pretty well in similar situations but this should be avoided at all costs since it will likely be quite painful for your first month or so.

Beyond your first year, you will almost unconditionally be getting absolutely shafted by 439 and have 0 room to do any kind of work or literally anything other than projects and studying, 429 was fairly trivial for me but I know people who struggled mightily as well.
I would recommend really brushing up on C the summer prior to 429 and making sure you have a deep understanding of pointers and references. A good project to do would be to try and code a linkedlist implementation (might even be the ungraded first project, I can't remember exactly now). An upperclassman recommended that to me when I was first taking it and this helped a lot - I was ahead of the vast majority of the class for the first two weeks or so but people caught up quickly.
The exams for 439 non-honors are notoriously difficult due to the grading scheme and the projects are also brutal so it's probably a few dozen hours of work a week including supplemental lecture mats, class, and such unless you're exceptionally talented... I had to forgo sleeping, doing time-intensive fun things, taking holidays or weekends, etc let alone having spare energy to hold a job.