(Like an idiot, I originally put this in the wrong forum.)

So, I recently have just gotten back into working out, as this past semester was pretty busy with nineteen credit hours and working thirty hours a week.

I'm currently pretty slim and would like to put on a bit more muscle and keep it toned, but when it comes to actual workout regimens, I'm a bit lost, in addition to the fact that I typically work out alone, given that most of my friends are gone for the summer while I'm taking classes.

I typically alternate days with upper and lower body workouts with some cardio thrown in, but having some structure would do me a world of good.

Any suggestions?