Personally I don't use pre workouts, Only thing I use is whey protein and that changes a lot, try different brands all the time.
Best thing to do is to try and eat well and a lot! Get a proper routine worked out for each muscle group and change it at least every 4 weeks incorporating different exercises, try to train at least 3 times a week!
Also a lot of people who start at the gym only work there upper body, You have to work your legs! Doing exercises like squats, deadlifts (back) leg press, basically most things to do with your legs helps raise your body's level of growth hormones!
I've been training 4 years and I'm pretty addicted to the gym, Keep it up and most importantly don't get tempted to touch roids!
