I don't know if there is a magic formula, to be honest. If you're in your 20s and you've had a shitty job for your short adult life, it's probably a lot easier to motivate yourself to get through college (perspective is an amazing thing). And sometimes motivation just comes naturally as you get older and you've been in college for a couple of years. I would argue that it's just important to survive, especially early on. Those first 2 years are tough, especially if you're adjusting to the college experience, life on your own, studying, adversity, etc. In my experience, I became more motivated as I moved further and further into my major; the gen ed stuff really didn't interest me that much, but once I got into the meat of mechanical/nuclear engineering, I became a lot more interested and motivated. I guess it also helped that by that point, I could also see the light at the end of the tunnel. And the promise of a big paycheck. For me, I just tried to survive until I got to the good stuff.
As far as the importance of GPA, that is debatable. I wasn't a business major, but as an engineer, GPA mattered when it came to 1) getting into the actual college of engineering and 2) finding an internship/co-op. Once I graduated, I learned that GPA wasn't nearly as important as I thought. I've hired a number of other engineers in the past decade, and I'm a lot less concerned about GPA; things like experience, personality, coachability, real knowledge, etc mean a lot more. As long as you've got decent grades (>3.0), you should be fine. I put a lot of pressure on myself at OSU to maintain a 4.0, and I remember how hard I was on myself when I got my first Bs. It took me a couple of years to realize that I stressed myself out way more than I should have. Again, sometimes you just have to survive in order to live to fight another day.
The best advice I could ever give a college student, especially one in their first year, is go to class. Regardless of the content or how easy it is, don't skip. It's important to treat college like a job, and keeping a regular routine is essential. I knew too many guys who would miss a class here or there (myself included), and that quickly turned into missing more and more classes. It's a slippery slope. It's amazing the advantages that students who actually show up for class end up with - you continue a routine, you're visible to your instructor(s), you won't miss out on anything in the class, and it makes studying a little easier. Plus you build relationships with other folks in class. And don't underestimate the visibility factor. I had a lot of professors, especially the further I got into my major, that noticed if I was in the front row vs. the back row, if I came to his office, if I asked good questions, etc. In other words, did I give a shit; they will often give you the benefit of the doubt if you show them that you do.