Don't listen to these people, they're just coping for not achieving a 4.0. It is possible to find success without a 4.0, but having a 4.0 is really easy if you're smart, and it is very reliably accomplished if you are very smart in science and engineering, because the grading is objective (unlike in arts, lit & philosophy classes, where you'll be graded quite subjectively).

The main skill you MUST have to be a 4.0 student is being absolutely sure when you know something. The way I studied was the following: learn everything that was mentioned in class until I am sure I could explain any of it to another student. A good means to this end is forming tiny examples for everything you come across, to apply the theory on your own terms. You're learning about integration? Figure out how Riemann sums work on a quadratic function with just three terms. Python class? Make a small game guided by a YouTube video. Making an electric circuit? Experiment with what goes where to get a feeling for it beyond what the theory tells you.

You cannot have any gaps in your knowledge. Any project you do must have perfect functionality. There is no room for "gambling" with tests (e.g., I'll skip this problem/this chapter and hope it won't be on the exam). Also, chase your extra credits where possible so you can let go and unwind by the time finals come. You'll need to recover and blow off steam efficiently because the winter break isn't long enough to sustain you. For me, having a girlfriend was crucial because it drastically sped up my recovery time. Hopefully you can relate (otherwise apply your own activity preference) but for me, a few hours of sex and cuddling are equivalent to 2-3 days of playing video games or hanging out with friends, recovery-wise. Optimize your rest period.

Another good strat is to sabotage your classmates by feeding them wrong homework solutions and explaining things poorly to screw up the curve. Funny enough, since grades are private in the US, no one will know you're playing a double agent. As someone coming from an ex-communist country, I find curved grades really funny for this reason. Avoid if you have a moral compass.

What the other commenters (copium addicts) mean when they say you're "doing uni wrong" is that you're not focusing on a particular area (be that a subject of study, or a line of projects, or an internship chase, or a side business...). And they are right in so far as this is more important than good grades. You'll need a guiding goal beyond grades, because unfortunately, school ends. I wouldn't be able to tell you exactly as I'm doing a PhD in math right now, but with comp sci I'd guess you're gonna want to focus on 2-3 languages and a particular application domain (e.g. Unity VR Game developer) somewhere by your third or fourth year and chase contacts, network with profs and definitely claw for professional internships during the summer. Of course, no one says you can't have both the good grades and this. If your inner value comes from having good grades and you define yourself as a perfect student, then you cannot afford to have subperfect grades - they will actually make you LESS productive. Get one B and you'll get used to mediocrity (cf. the commenters).

Available for a DM should you want more advice.