WisdomTreeBut university is lot more of demanding and a lot more goes into it, you're unlikely to do good just by gaming after coming back from class...
Seems like you answered your own question here.
You're totally right in that you can't just leave class, head home, and start gaming. The best thing to do is work first, play later. If that means homework, then your goal should be fairly concrete. Determine how many days you have to do the assignments you have at a given point and allot yourself the time to do that much work before you even think about coming home to your computer. Make sure you give yourself more than enough time to make those deadlines. You want to avoid stuff like pulling all nighters, or leaving mumble as soon as a scrim ends to hurry and make a 12 A.M. cutoff. It's not worth the stress and you're better off getting it done during the day. Also, try to stay on campus and work independent of your home/dorm room/whatever as much as humanly possible. The temptation to fuck around on your computer is difficult to fight if you're anything like me. It takes a lot of willpower to stare down a gaming rig when you have homework to do and NOT boot up anything that'll take your mind off of your responsibilities.
As for studying, it's a little more complicated. As a freshman, it may take you a bit to determine if your starting classes are actually difficult enough to study intensively for. I'd be lying to you if I said that I have had to study to get good grades in certain classes; some really are just so easy or have such a lax rubric that you can get a good grade without setting time aside to study. So just get a feel for your classes; don't get overconfident but don't overload yourself with two hour long study sessions in classes you may not actually need to study intensively for.
And as a side note, try to leave time for social stuff as well. It's difficult to maintain balance between work, social stuff, games, and sleep, but it is possible. I suggest looking around for at least one club that seems cool. Depending on the size of your campus, there could be some really niche stuff. One of my friends has a club entirely dedicated to just playing Smash 4 and nothing else.