I just finished my freshman year in aerospace engineering with a 4.0 GPA. I concur with most of the things that have already been stated. I also say go to the teacher for help if you possibly can. As for “lighter” classes - one thing you could do is see if any Gen eds are offered as 8 week classes for the first half of the semester. I took one of them that way, and after the first 8 weeks, my load dropped down and made the last half the the semester more manageable. Also, some classes are just going to be crazy. I had my first AE class this semester, which I’d heard horror stories about. It was a very hard class, but you just had to get used to the fact that a D on those tests was a respectable score (the teacher graded on a curve.)
Being ahead in the math sequence definitely helps. If you can get credit for Calc I & II, do so.
Also, the best way to help your friends is to complete the assignments early and be ready when they ask. 